Silica

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Worker exposure to silica in construction projects is a significant concern because silica is one of the main constituents of many construction materials. Prolonged or repeated exposure to uncombined crystalline silica at airborne concentrations above established occupational exposure limits can cause damage to lungs (silicosis) and may cause cancer.

Construction materials containing silica include:

  • abrasives used for blasting (sandblasting)
  • concrete, concrete block, cement, mortar
  • brick, refractory brick
  • granite, sandstone, quartzite, slate
  • gunite (a mixture of water, cement, and sand)
  • mineral deposits
  • stone and rock
  • sand, soil and fill dirt
  • asphalt containing rock or stone

Many construction activities and processes release airborne silica-containing dust. Abrasive blasting generates the most dust. Abrasive blasting is the cleaning, smoothing, roughening or removing of part of the surface of any article by using a jet of sand, metal shot, grit or other material. Exposure to silica from abrasive blasting can occur if the abrasive contains silica (sandblasting). Exposure to silica from abrasive blasting can also occur if the material being blasted contains silica. Other processes that generate airborne dust include:

  • rock excavating and processing activities such as:
    • cutting, splitting, chipping, hammering, drilling, crushing, sieving, loading, hauling, and dumping of gravel or rock that contains more than 5% crystalline silica
  • concrete and masonry activities such as:
    • sawing, hammering, drilling, grinding, and chipping and demolition of concrete and masonry structures
  • dry sweeping or pressurized air blowing of concrete, rock, or sand dust
  • road construction
  • sweeping, cleaning, and dismantling equipment
  • tunneling, excavation, and earth moving high silica-containing soils.

An employer or contractor shall:

  • Warn workers about the health hazards associated with inhaling dust containing silica if any part of their work will involve a silica process or if the workers are likely to be exposed to silica dust.
  • Take all practicable steps to prevent inhalation of silica dust or dissemination of silica dust into the air of the workplace during cleaning or maintenance of:
    • any blasting equipment
    • blasting enclosure
    • ventilating system
    • separating equipment
  • Ensure all worksites and work-related areas are regularly cleaned where dust from a silica process may affect the health or safety of workers.
  • Ensure that silica dust from a silica process other than abrasive blasting, is prevented as far as practicable, from entering the air where workers may be present by providing:
    • total or partial enclosure of the process;
    • efficient local exhaust ventilation;
    • jets or sprays of a suitable wetting agent; or
    • any other method that provides equivalent protection to workers.
  • Ensure that any enclosure, apparatus or exhaust-ventilation equipment provided is:
    • Maintained;
    • Inspected daily when in use;
    • Certified as safe and effective by a competent person at least annually.
  • Ensure that no air discharged from a local exhaust ventilation system recirculates in the work place unless the air passes through an effective dust removal system. The system must be equipped with a warning device that alerts workers when it malfunctions.
  • Isolate workers, where practicable, from any air containing dust released from a silica process that cannot practicably be prevented.
  • Provide and ensure workers wear respiratory protective devices and other personal protective equipment meeting the requirements of PART VII where:
    • Protective measures set out in section 351 and 352 are not practicable; or
    • Workers doing cleaning and maintenance work may be exposed to dust from a silica process.
  • Provide and maintain approved blasting hoods for workers doing abrasive blasting. The air supply must be delivered at a volume of at least 170 litres per minute (l/min) and at a pressure less than 140 kilopascals (kPa).
  • Provide and maintain respiratory protective devices meeting requirements of Part VII for workers possibly exposed to dust from abrasive blasting.
  • Ensure that every blasting enclosure is:
    • constructed, operated and maintained to prevent the escape of dust;
    • provided with an efficient, dust-extraction system, operating continuously whenever blasting enclosure is in use, whether or not abrasive blasting is taking place;
    • provided with efficient equipment for separating abrasive from dust, where practicable.
  • Ensure that an abrasive is not reintroduced into a blasting apparatus until the abrasive has been separated from the dust.
  • Ensure that:
    • blasting enclosure is inspected daily when in use;
    • a competent person thoroughly and regularly examines and tests a blasting enclosure, connected equipment, and associated ventilating system;
    • all identified defects are remedied immediately.
  • Ensure that a competent person must record the results of their examinations and tests of a blasting enclosure, connected equipment, and associated ventilating system.
  • Ensure that:
    • No abrasive blasting of articles that may produce dust containing uncombined silica is done in a blasting enclosure, where practicable;
    • No sand or other substance containing more than 1% by weight of uncombined silica is used for abrasive blasting in a blasting enclosure, where practicable;
    • Only abrasive blasting and work immediately incidental to abrasive blasting, and, cleaning and maintenance of the blasting enclosure, connected equipment, and the associated ventilating system are performed in a blasting enclosure.
  • Ensure that no sandblasting is done to any article outside a blasting enclosure if sandblasting can be done in a blasting enclosure, where reasonably practicable.
  • Ensure that no sandblasting is done inside any structure or confined space without written permission of the director and complying with any conditions specified by the director.
  • Ensure that no silica flour is used;
    • for any purpose if it can be substituted with a less hazardous substance; or
    • in the manufacturing of scouring powder or abrasive soap or an abrasive in any process.
  • Arrange, no more than once a year, a medical examination for a worker regularly working in a silica process. The medical examination must be requested by the worker and conducted during the worker’s normal working hours.
  • Reimburse the worker for any part of the medical examination costs that the worker cannot recover.
  • Credit a worker’s attendance at a medical examination as time at work when the worker cannot attend a medical examination during their normal working hours and ensure that the worker does not lose any pay or other benefits.
  • Ensure that a worker’s medical examination includes:
    • a comprehensive medical history and physical examination with special attention to the respiratory system;
    • lung-function tests, including forced vital capacity and forced expiratory volume at one second;
    • any further medical investigations necessary for the diagnosis of a silica-related disease.

An owner shall:

  • Take all practicable steps to prevent inhalation of silica dust or dissemination of silica dust into the air of the workplace during cleaning or maintenance of:
    • any blasting equipment
    • blasting enclosure
    • ventilating system
    • separating equipment
  • If mining is carried out underground in strata containing uncombined silica in a crystalline form, an employer or contractor shall:
    • minimize the release of dust into the general mine air during construction, use and maintenance of every ore pass, if reasonably practicable;
    • provide an effective means to spray water within a suitable distance of the working face of every drift or raise to suppress any dust;
    • spray water for a minimum of 15 minutes after any blasting operation is complete;
    • provide every drill with a water jet, spray or other suitable attachment to prevent dust from escaping and ensure that the attachment is used at all times during a drilling operation.

Contamination Limits

CAS Number Substance 8 hour average contamination limit mg/m³* or ppm* 15 minute average contamination limit mg/m³* or ppm* Notation
  Silica Amorphous:      
69012-46-2 Silica, fume (respirable fraction) 2 mg/m3    
60676-86-0 Silica, fused (respirable fraction) 0.1 mg/m3    
  Silica - Crystalline#:      
14464-46-1 Cristobalite (respirable fraction)      
14808-60-7 Quartz (respirable fraction)      
1317-95-9 Tripoli, as quartz (respirable fraction)      
*mg/m3 - milligrams of substance per cubic meter of air; ppm - parts (volume) of substance per million parts (volume) of air

**C - ceiling limit.

# - Trydimite removed.

Respirable fraction:

For the application of this limit, the respirable fraction is that fraction of the aerosol that passes a size selector with the following characteristics:

Table B

Particle Aerodynamic Diameter (µm) Respirable Particle Mass (RPM) (%)
0
100
1
97
2
91
3
74
4
50
5
30
6
17
7
9
8
5
10
1

Occupational Health and Safety Regulations, 1996
S.S., c. O-1.1, Reg 1

Part I Preliminary Matters

Section 2 Interpretation

2. (1) In these regulations and in all other regulations made pursuant to the Act:

(a) "Act" means The Occupational Health and Safety Act, 1993 ;

(b) "air-purifying respirator" means a respirator that removes airborne contaminants from the air inhaled by a worker;

(c) "approved" means:

(i) approved by an agency acceptable to the director for use under the conditions prescribed by the agency; or

(ii) approved conditionally or otherwise by a certificate of the director;

(d) "atmosphere-supplying respirator" means a respirator that delivers clean breathing air to a worker from a compressor or a cylinder, an SCBA, whether closed or open circuit, or a combination of SCBA and supplied air;

(e) "borehole" means a mechanically drilled hole in the ground;

(f) "building shaft" means a continuous vertical space substantially enclosed on all sides that extends for two or more floors, and includes an elevator shaft, a ventilation shaft, a stairwell and a service shaft;

(g) "class A qualification" means a certificate or certificates that:

(i) are issued by an agency, as defined in section 50, with respect to the successful completion of a first aid training course and a cardiopulmonary resuscitation training course that meet the minimum requirements for course duration and content set out in Table 1 of the Appendix; and

(ii) qualify the holder to perform the services set out in Table 2 of the Appendix;

(h) "class B qualification" means a certificate or certificates that:

(i) are issued by an agency, as defined in section 50, with respect to the successful completion of a first aid training course and a cardiopulmonary resuscitation training course that meet the minimum requirements for course duration and content set out in Table 3 of the Appendix; and

(ii) qualify the holder to perform the services set out in Table 4 of the Appendix;

(i) "Class C fire" means a fire involving energized electrical equipment;

(j) "co-chairpersons" means, with respect to a committee, the employer or contractor co-chairperson appointed pursuant to clause 43(1)(b) and the worker co-chairperson elected pursuant to clause 43(1)(a);

(k) "committee" means an occupational health committee;

(l) "competent" means possessing knowledge, experience and training to perform a specific duty;

(m) "competent worker", with respect to a particular task or duty, includes a worker who is being trained to perform that task or carry out that duty and who is under close and competent supervision during that training;

(n) "connecting linkage" means a lanyard, safety hook, cable or connector inserted between a personal fall arrest system and the D-ring on a worker's full-body harness;

(o) "construction" means the erection, alteration, renovation, repair, dismantling, demolition, structural maintenance and painting of a structure, and includes:

(i) land clearing, earth moving, grading, excavating, trenching, digging, boring, drilling, blasting and concreting; and

(ii) the installation of any plant;

(p) "controlled product" means a controlled product within the meaning of the Hazardous Products Act (Canada);

(q) "dBA" means the sound pressure level in decibels measured on the A scale of a sound level meter;

(r) "dBA Lex" means the level of a worker's total exposure to noise, in dBA, averaged over an entire workday and adjusted to an equivalent eight-hour exposure;

(s) "designated signaller" means a worker designated pursuant to clause 132(1)(a) to give signals;

(t) "emergency medical technician" means a person who is licensed as an emergency medical technician, emergency medical technician-advanced or emergency medical technician-paramedic pursuant to The Ambulance Act;

(u) "escape respirator" means an atmosphere-supplying respirator or an air-purifying respirator that is designed to be used by a worker for escape purposes only;

(v) "excavated shaft" means a dug-out passage into the ground, the longest dimension of which exceeds 1.5 metres and of which the acute angle between the axis of the longest dimension and the vertical is less than 45;

(w) "excavation" means any dug-out area of ground other than a trench, tunnel or excavated shaft;

(x) "fall-arresting device" Repealed. [Sask. Reg. 67/2007, s. 3]

(y) "first aid" means immediate assistance given in case of injury until medical aid has been obtained;

(z) "first aid attendant" means the holder of a valid:

(i) class A qualification;

(ii) class B qualification;

(iii) emergency medical technician's licence; or

(iv) licence, certificate or other qualification that, in the opinion of the director, is equivalent to or superior to a qualification set out in subclauses (i) to (iii);

(aa) "first aid register" means the register required by section 57;

(bb) "first aid station" means a work-related area containing the supplies and equipment required by subsection 56(1);

(bb.1) "forklift" means a self-propelled machine that has a power-operated upright, angled or telescoping lifting device that can raise and lower a load for the purpose of transporting or stacking;

(cc) "full-body harness" means a safety device that is capable of suspending a worker without causing the worker to bend at the waist, and consists of straps that pass over the worker's shoulders and around the worker's legs, an upper dorsal suspension assembly and all integral hardware;

(dd) "hand tool" means hand-held equipment that is powered by the energy of a worker;

(ee) "harmful" means known to cause harm or injury;

(ff) "hazardous" means likely to cause harm or injury in certain circumstances;

(gg) "HEPA filter" means a high-efficiency particulate aerosol filter that is at least 99.97% efficient in collecting a 0.3 micrometre aerosol;

(hh) "hoist" means a machine that consists of a raising and lowering mechanism;

(ii) "immediately dangerous to life or health" means a condition in which a hazardous atmosphere exists to such an extent that a worker who is not using an approved respiratory protective device will suffer escape-impairing or irreversible health effects if the worker does not leave the hazardous atmosphere within 30 minutes;

(jj) "instruct" means to give information and direction to a worker with respect to particular subject-matter;

(kk) "lifeline" means a length of rope or strap that is attached to a safe point of anchorage at one end or, in the case of a horizontal lifeline, at both ends to provide support and a guide for a personal fall arrest system or personnel lowering device;

(ll) "locked out" means to have isolated the energy source or sources from equipment, to have dissipated any residual energy in a system and to have secured the isolation by a device that is operated by a key or other process;

(mm) "machine" means any combination of mechanical parts that transmits from one part to another or otherwise modifies force, motion or energy;

(nn) "maintained" means kept in a condition of efficient and safe functioning by a system of regular examination, testing and servicing or repair;

(oo) "The Mines Regulations" means The Mines Regulations, 2003 ;

(pp) "officer" means an occupational health officer;

(qq) "operator" means a person who operates any equipment;

(qq.1) "percutaneous" means a route of entry that is through the skin or mucous membrane, and includes subcutaneous, intramuscular and intravascular routes of entry.

(qq.2) "personal fall arrest system" means personal protective equipment that provides a means of safely arresting the fall of a worker and that, subsequent to the arrest of the fall, does not by itself permit the further release or lowering of the worker;

(rr) "personal protective equipment" means any clothing, device or other article that is intended to be worn or used by a worker to prevent injury or to facilitate rescue;

(ss) "personnel lowering device" means a device that provides a means of lowering a worker from a height at a controlled rate of descent;

(tt) "power tool" means a hand-held machine that is powered by energy other than the energy of a worker;

(uu) "powered mobile equipment" means a self-propelled machine or a combination of machines, including a prime mover, that is designed to manipulate or move materials or to provide a work platform for workers;

(vv) "professional engineer" means an engineer who is registered pursuant to The Engineering Profession Act;

(ww) "public highway" means a public highway as defined in The Highways and Transportation Act, 1997 ;

(xx) "qualified" means possessing a recognized degree, a recognized certificate or a recognized professional standing and demonstrating, by knowledge, training and experience, the ability to deal with problems related to the subject-matter, the work or the project;

(yy) "representative" means an occupational health and safety representative;

(zz) "respiratory protective device" means a device that is designed to protect a wearer from inhaling a hazardous atmosphere, and includes an atmosphere-supplying respirator, an air-purifying respirator and an escape respirator;

(aaa) "safeguard" means a guard, shield, wire mesh, guardrail, gate, barrier, safety net, handrail or other similar equipment that is designed to protect the safety of workers, but does not include personal protective equipment;

(bbb) "safety belt" Repealed. [Sask. Reg. 67/2007, s. 3]

(ccc) "SCBA" means self-contained breathing apparatus;

(ddd) "supervisor" means a person who is authorized by an employer to oversee or direct the work of workers;

(eee) "train" means to give information and explanation to a worker with respect to a particular subject-matter and require a practical demonstration that the worker has acquired knowledge or skill related to the subject-matter;

(fff) "travelway" means any place where workers or vehicles regularly travel or pass, and includes a ramp, runway, catwalk, bridge, conveyor, gantry or passage;

(ggg) "trench" means an elongated dug-out area of land whose depth exceeds its width at the bottom;

(hhh) "tunnel" means an underground passage that has an incline of not more than 45 from the horizontal;

(iii) "vehicle" means a machine in, on or by which a person or thing may be transported, and includes powered mobile equipment;

(jjj) "work" and "at work" means:

(i) the time during which a worker is in the course of the worker's employment; or

(ii) the time that a self-employed person devotes to work as a self-employed person;

(kkk) "work-related area" means all places that are ancillary to a place of employment, and includes lunchrooms, restrooms, first aid rooms, lecture rooms, parking lots under the control of the employer or contractor, offices and work camp living accommodations, but does not include a permanent living accommodation.

(2) For the purposes of the Act and in these regulations and all other regulations made pursuant to the Act, "injury" includes any disease and any impairment of the physical or mental condition of a person.

(3) Any word or expression used but not defined in these regulations or the Act has the meaning commonly given to it at places of employment in the industry concerned.

(4) Unless otherwise expressly stated:

(a) lumber sizes specified in these regulations are lumber sizes after dressing; and

(b) "lumber" means lumber that is free of visible defects.

[Sask. Reg. 6/97, s. 3; 35/2003, s. 3; 112/2005, s. 3; 67/2007, s. 3]

3. Repealed. [Sask. Reg. 35/2003, s. 4]

Part XXIV Silica Processes and Abrasive Blasting

Section 348 Warning of workers

348. An employer shall warn all workers who, in the course of employment, are likely to be engaged in a silica process or are likely to be exposed to silica dust of the dangers to health from the inhalation of dust containing silica.

Section 349 Cleaning of blasting equipment, etc.

349. An employer, contractor or owner shall take all practicable steps to prevent the inhalation of silica dust or the dissemination of silica dust into the air of the place of employment during the cleaning or maintenance of any blasting equipment, blasting enclosure, ventilating system or separating equipment.

Section 350 Cleaning of worksites

350. An employer or contractor shall ensure that all worksites and work-related areas where dust from a silica process may affect the health or safety of a worker are regularly cleaned using a vacuum that has a HEPA filter on the exhaust or, where a vacuum is not practicable, by using wet methods.

Section 351 Silica processes other than abrasive blasting

351. (1) Where a silica process other than abrasive blasting is carried on, an employer or contractor shall ensure that the entry of dust into the air where workers may be present is prevented, to the extent that is practicable, by the provision of:

(a) total or partial enclosure of the process;

(b) efficient local exhaust ventilation;

(c) jets or sprays of a suitable wetting agent; or

(d) any other method that provides equivalent protection to the workers.

(2) An employer or contractor shall ensure that any enclosure, apparatus or exhaust-ventilation equipment provided pursuant to subsection (1) is:

(a) maintained in accordance with subsections 67(2) and (3);

(b) inspected daily when in use; and

(c) certified as safe and effective by a competent person at least once each year.

(3) An employer or contractor shall ensure that no air discharged from a ventilation system provided pursuant to subsection (1) is recirculated in the place of employment unless the air is passed through an effective dust removal system equipped with a device that will provide a warning to workers when the system is not working effectively.

[Sask. Reg. 6/97, s. 12]

Section 352 Isolation from air containing dust

352. Where it is not practicable to prevent the entry into the air of dust from a silica process, an employer or contractor shall, where it is practicable, provide for the isolation of workers from the air containing the dust.

Section 353 Personal protective equipment

353. (1) An employer or contractor shall provide, and require a worker to wear, a respiratory protective device and other personal protective equipment that meet the requirements of Part VII where:

(a) the protective measures required by section 351 or 352 are not practicable; or

(b) the worker is employed in cleaning and maintenance work and may be exposed to dust from a silica process.

(2) For workers engaged in abrasive blasting, an employer or contractor shall provide and maintain approved blasting hoods supplied with air:

(a) of a volume of not less than 170 litres per minute at a pressure of not more than 140 kilopascals; and

(b) that is clean and at a reasonable temperature.

(3) For workers who may be exposed to dust resulting from abrasive blasting, an employer or contractor shall provide and maintain respiratory protective devices that meet the requirements of Part VII.

Section 354 Standards for blasting enclosures

354. (1) An employer or contractor shall ensure that every blasting enclosure is:

(a) constructed, operated and maintained to prevent the escape of dust;

(b) provided with an efficient, dust-extraction system, that is operated continuously whenever the blasting enclosure is in use, whether or not abrasive blasting is actually taking place; and

(c) provided with efficient equipment for separating the abrasive from the dust, to the extent that is practicable.

(2) An employer or contractor shall ensure that an abrasive is not reintroduced into a blasting apparatus until the abrasive has been separated from the dust pursuant to clause (1)(c).

(3) An employer or contractor shall ensure that:

(a) a blasting enclosure is inspected daily when in use;

(b) a blasting enclosure, the equipment connected with the enclosure and the ventilating system associated with the enclosure are thoroughly examined and tested regularly by a competent person; and

(c) all defects identified pursuant to this section are remedied immediately.

(4) A competent person who carries out examinations and testing pursuant to clause (3)(b) shall record the results of those examinations and tests.

Section 355 Use of blasting enclosures

355. An employer or contractor shall ensure that:

(a) to the extent that is practicable, no abrasive blasting of articles that are likely to give rise to dust containing uncombined silica is done other than in a blasting enclosure;

(b) where practicable, no sand or other substance containing more than 1% by weight of uncombined silica is used for abrasive blasting in a blasting enclosure; and

(c) no work is performed in a blasting enclosure except:

(i) abrasive blasting and work immediately incidental to abrasive blasting; and

(ii) cleaning and maintenance of the blasting enclosure, the equipment associated with the blasting enclosure and the ventilation system.

Section 356 Sandblasting

356. (1) An employer or contractor shall ensure that no sandblasting is done to any article outside a blasting enclosure where it is reasonably practicable to introduce the article into a blasting enclosure.

(2) An employer or contractor shall ensure that no sandblasting is done inside any structure or confined space without:

(a) obtaining the written permission of the director; and

(b) complying with any conditions that the director may specify.

Section 357 Silica flour

357. An employer or contractor shall ensure that no silica flour is used:

(a) for any purpose for which a less hazardous substance may be substituted; or

(b) in the manufacture of scouring powder or abrasive soaps or as an abrasive in any process.

Section 358 Medical examinations

358. (1) In this section, "worker" means a worker who is regularly employed in a silica process.

(1.1) Not less than once every two years and with consent of the worker, the employer shall:

(a) offer to arrange for a medical examination of the worker during the worker's normal working hours; and

(b) reimburse the worker for any part of the cost of the medical examination that the worker cannot recover.

(2) Where a worker cannot attend a medical examination mentioned in subsection (1.1) during the worker's normal working hours, an employer shall credit the worker's attendance at the examination as time at work and ensure that the worker does not lose any pay or other benefits.

(3) A medical examination arranged pursuant to subsection (1.1) must include:

(a) a comprehensive medical history and physical examination with special attention to the respiratory system;

(b) lung-function tests, including forced vital capacity and forced expiratory volume at one second; and

(c) any further medical investigations that are necessary for the diagnosis of a silica-related disease.

[Sask. Reg. 67/2007, s. 27]

Part XXXIII Repeal, Transitional and Coming into Force

Schedule Table 21 Contamination Limits

[Sections 307 and 309, clause 346(f)]

Also check Tables 19 and 20 for substances (such as asbestos and benzene) with additional requirements

Table

CAS Number Substance 8 hour average contamination limit mg/m³* or ppm* 15 minute average contamination limit mg/m³* or ppm* Notation+
75-07-0 Acetaldehyde **C25 ppm T20
64-19-7 Acetic acid 10 ppm 15 ppm
108-24-7 Acetic anhydride 5 ppm 10 ppm
67-64-1 Acetone 500 ppm 750 ppm
75-86-5 Acetone cyanohydrin, as CN **C5 mg/m3 Skin
75-05-8 Acetonitrile 20 ppm 30 ppm Skin
98-86-2 Acetophenone 10 ppm 15 ppm
79-27-6 Acetylene tetrabromide 1 ppm 3 ppm
50-78-2 Acetylsalicylic acid 5 mg/m3 10 mg/m3
107-02-8 Acrolein **C0.1 ppm Skin
79-06-1 Acrylamide (inhalable fraction++ and vapour) 0.03 mg/m3 0.09 mg/m3 T20, Skin
79-10-7 Acrylic acid 2 ppm 4 ppm Skin
107-13-1 Acrylonitrile 2 ppm 4 ppm Skin, T20
124-04-9 Adipic acid 5 mg/m3 10 mg/m3
111-69-3 Adiponitrile 2 ppm 4 ppm Skin
309-00-2 Aldrin 0.25 mg/m3 0.75 mg/m3 Skin
Aliphatic hydrocarbon gases, Alkane [C1-C4] 1000 ppm 1250 ppm
107-18-6 Allyl alcohol 0.5 ppm 1.5 ppm Skin
107-05-1 Allyl chloride 1 ppm 2 ppm
106-92-3 Allyl glycidyl ether (AGE) 1 ppm 3 ppm
2179-59-1 Allyl propyl disulphide 0.5 ppm 1.5 ppm SEN
7429-90-5 Aluminum and compounds (as Al):
Metal dust 10 mg/m3 20 mg/m3
Pyro powders 5 mg/m3 10 mg/m3
Soluble salts 2 mg/m3 4 mg/m3
Alkyls, not otherwise specified 2 mg/m3 4 mg/m3
1344-28-1 Aluminum oxide 10 mg/m3 20 mg/m3
504-29-0 2-Aminopyridine 0.5 ppm 1.0 ppm
61-82-5 Amitrole 0.2 mg/m3 0.6 mg/m3 T20
7664-41-7 Ammonia 25 ppm 35 ppm
12125-02-9 Ammonium chloride fume 10 mg/m3 20 mg/m3
3825-26-1 Ammonium perfluorooctanoate 0.01 mg/m3 0.03 mg/m3 Skin
7773-06-0 Ammonium sulphamate (Ammate) 10 mg/m3 20 mg/m3
994-05-8 tert-Amyl methyl ether (TAME) 20 ppm 30 ppm
62-53-3 Aniline 2 ppm 4 ppm Skin
90-04-0 o-Anisidine 0.5 mg/m3 1.5 mg/m3 Skin, T20
104-94-9 p-Anisidine 0.5 mg/m3 1.5 mg/m3 Skin
7440-36-0 Antimony and compounds, (as Sb) 0.5 mg/m3 1.5 mg/m3
86-88-4 ANTU (alpha-Naphthyl thiourea) 0.3 mg/m3 0.9 mg/m3
7440-38-2 Arsenic, and inorganic compounds, (as As) 0.01 mg/m3 0.03 mg/m3 T20
7784-42-1 Arsine 0.05 ppm 0.15 ppm
8052-42-4 Asphalt (bitumen) fume, as benzene soluble aerosol (inhalable fraction++) 0.5 mg/m3 1.5 mg/m3
1912-24-9 Atrazine 5 mg/m3 10 mg/m3 T20
86-50-0 Azinphos-methyl (inhalable fraction++ and vapour) 0.2 mg/m3 0.6 mg/m3 Skin; SEN
7440-39-3 Barium and soluble compounds, (as Ba) 0.5 mg/m3 1.5 mg/m3
7727-43-7 Barium sulphate 10 mg/m3 20 mg/m3
17804-35-2 Benomyl 10 mg/m3 20 mg/m3
98-07-7 Benzotrichloride **C0.1 ppm Skin, T20
98-88-4 Benzoyl chloride **C0.5 ppm T20
94-36-0 Benzoyl peroxide 5 mg/m3 10 mg/m3
140-11-4 Benzyl acetate 10 ppm 20 ppm
100-44-7 Benzyl chloride 1 ppm 2 ppm T20
7440-41-7 Beryllium and compounds, (as Be) 0.002 mg/m3 0.01 mg/m3 T20
92-52-4 Biphenyl (diphenyl) 0.2 ppm 0.6 ppm
3033-62-3 Bis (2-dimethylaminoethyl)ether (DMAEE) 0.05 ppm 0.15 ppm Skin
1304-82-1 Bismuth telluride
Undoped 10 mg/m3 20 mg/m3
Se-doped, as Bi2Te3 5 mg/m3 10 mg/m3
1330-43-4; 1303-96-4; 10043-35-3; 12179-04-3 Borate compounds, inorganic (inhalable fraction++) 2 mg/m3 6 mg/m3
1303-86-2 Boron oxide 10 mg/m3 20 mg/m3
10294-33-4 Boron tribromide **C1 ppm
7637-07-2 Boron trifluoride **C1 ppm
314-40-9 Bromacil 10 mg/m3 20 mg/m3
7726-95-6 Bromine 0.1 ppm 0.2 ppm
7789-30-2 Bromine pentafluoride 0.1 ppm 0.3 ppm
74-97-5 Bromochloromethane (Chlorobromomethane) 200 ppm 250 ppm
75-25-2 Bromoform 0.5 ppm 1.5 ppm Skin
106-94-5 1-Bromopropane 10 ppm 20 ppm
106-99-0 1,3-Butadiene 2 ppm 4 ppm T20
106-97-8; 75-28-5 Butane, All isomers See Aliphatic hydrocarbon gases [C1-C4]
111-76-2 2-Butoxyethanol (Butyl Cellosolve or EGBE) 20 ppm 30 ppm
112-07-2 2-Butoxyethyl acetate (EGBEA) 20 ppm 30 ppm
123-86-4 n-Butyl acetate 150 ppm 200 ppm
105-46-4 sec-Butyl acetate 200 ppm 250 ppm
540-88-5 tert-Butyl acetate 200 ppm 250 ppm
141-32-2 n-Butyl acrylate 2 ppm 4 ppm SEN
71-36-3 n-Butyl alcohol (n-butanol) 20 ppm 30 ppm
78-92-2 sec-Butyl alcohol (sec-butanol) 100 ppm 125 ppm
75-65-0 tert-Butyl alcohol (tert-butanol) 100 ppm 125 ppm
109-73-9 n-Butylamine **C5 ppm Skin
1189-85-1 tert-Butyl chromate, (as Cr03) **C0.1 mg/m3 Skin
2426-08-6 n-Butyl glycidyl ether (BGE) 3 ppm 6 ppm Skin, SEN
138-22-7 n-Butyl lactate 5 ppm 10 ppm
109-79-5 n-Butyl mercaptan 0.5 ppm 1.5 ppm
89-72-5 o-sec-Butylphenol 5 ppm 7 ppm Skin
98-51-1 p-tert-Butyltoluene 1 ppm 2 ppm
7440-43-9 Cadmium, and compounds, (as Cd): T20
(total fraction) 0.01 mg/m3 0.03 mg/m3
(respirable fraction++) 0.002 mg/m3 0.006 mg/m3
1317-65-3 Calcium carbonate 10 mg/m3 20 mg/m3
13765-19-0 Calcium chromate, (as Cr) 0.001 mg/m3 0.003 mg/m3
156-62-7 Calcium cyanamide 0.5 mg/m3 1.5 mg/m3
1305-62-0 Calcium hydroxide 5 mg/m3 10 mg/m3
1305-78-8 Calcium oxide 2 mg/m3 4 mg/m3
1344-95-2 Calcium silicate, synthetic nonfibrous 10 mg/m3 20 mg/m3
76-22-2 Camphor, synthetic 2 ppm 3 ppm
105-60-2 Caprolactam (inhalable fraction++ and vapour) 5 mg/m3 10 mg/m3
2425-06-1 Captafol 0.1 mg/m3 0.3 mg/m3 Skin, T20
133-06-2 Captan (inhalable fraction++) 5 mg/m3 10 mg/m3 SEN
63-25-2 Carbaryl 5 mg/m3 10 mg/m3
1563-66-2 Carbofuran (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3
1333-86-4 Carbon black 3.5 mg/m3 7 mg/m3
124-38-9 Carbon dioxide 5000 ppm 30,000 ppm
75-15-0 Carbon disulphide 10 ppm 15 ppm Skin
630-08-0 Carbon monoxide 25 ppm 190 ppm
558-13-4 Carbon tetrabromide 0.1 ppm 0.3 ppm
75-44-5 Carbonyl chloride (Phosgene) 0.1 ppm 0.3 ppm
353-50-4 Carbonyl fluoride 2 ppm 5 ppm
120-80-9 Catechol (Pyrocatechol) 5 ppm 7.8 ppm Skin
9004-34-6 Cellulose (paper fibre) 10 mg/m3 20 mg/m3
21351-79-1 Cesium hydroxide 2 mg/m3 4 mg/m3
57-74-9 Chlordane 0.5 mg/m3 1.5 mg/m3 Skin
8001-35-2 Chlorinated camphene 0.5 mg/m3 1 mg/m3 Skin, T20
31242-93-0 o-Chlorinated diphenyl oxide 0.5 mg/m3 1.5 mg/m3
7782-50-5 Chlorine 0.5 ppm 1 ppm
10049-04-4 Chlorine dioxide 0.1 ppm 0.3 ppm
7790-91-2 Chlorine trifluoride **C 0.1 ppm
107-20-0 Chloroacetaldehyde **C1 ppm
78-95-5 Chloroacetone **C1 ppm Skin
532-27-4 alpha-Chloroacetophenone (Phenacyl chloride) 0.05 ppm 0.15 ppm
79-04-9 Chloroacetyl chloride 0.05 ppm 0.15 ppm Skin
108-90-7 Chlorobenzene (Monochlorobenzene) 10 ppm 15 ppm
2698-41-1 o-Chlorobenzylidene malononitrile **C0.05 ppm Skin
126-99-8 2-Chloro-1,3-butadiene (beta-Chloroprene) 10 ppm 15 ppm Skin
75-45-6 Chlorodifluoromethane 1000 ppm 1250 ppm
53469-21-9 Chlorodiphenyl (42% chlorine) 1 mg/m3 3 mg/m3 Skin
11097-69-1 Chlorodiphenyl (54% chlorine) 0.5 mg/m3 1.5 mg/m3 Skin
107-07-3 2-Chloroethanol (Ethylene chlorohydrin) **C1.0 ppm Skin
600-25-9 1-Chloro-1-nitropropane 2 ppm 4 ppm
76-15-3 Chloropentafluoroethane 1000 ppm 1250 ppm
76-06-2 Chloropicrin 0.1 ppm 0.3 ppm
127-00-4; 78-89-7 1-Chloro-2-propanol and 2- Chloro-1-propanol 1 ppm 3 ppm Skin
598-78-7 2-Chloropropionic acid 0.1 ppm 0.3 ppm Skin
2039-87-4 o-Chlorostyrene 50 ppm 75 ppm
95-49-8 o-Chlorotoluene 50 ppm 65 ppm
2921-88-2 Chlorpyrifos, (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3 Skin
7440-47-3 Chromium metal and inorganic compounds, (as Cr):
Metal and Cr (III) compounds 0.5 mg/m3 1.5 mg/m3
Water soluble Cr (VI) compounds 0.05 mg/m3 0.15 mg/m3 T20
Insoluble Cr (VI) compounds 0.01 mg/m3 0.03 mg/m3 T20
14977-61-8 Chromyl chloride 0.025 ppm 0.07 ppm
2971-90-6 Clopidol 10 mg/m3 20 mg/m3
Coal dust:
Anthracite (respirable fraction++) 0.4 mg/m3 1.2 mg/m3
Bituminous (respirable fraction++) 0.9 mg/m3 2.7 mg/m3
65996-93-2 Coal tar pitch volatiles, as benzene soluble aerosol (See Particulate polycyclic aromatic hydrocarbons) 0.2 mg/m3 0.6 mg/m3 T20
7440-48-4 Cobalt and inorganic compounds, (as Co) 0.02 mg/m3 0.06 mg/m3 T20
10210-68-1 Cobalt carbonyl, (as Co) 0.1 mg/m3 0.3 mg/m3
16842-03-8 Cobalt hydrocarbonyl, (as Co) 0.1 mg/m3 0.3 mg/m3
7440-50-8 Copper, (as Cu):
fume 0.2 mg/m3 0.6 mg/m3
dusts and mists 1 mg/m3 3 mg/m3
----- Cotton dust, raw 0.2 mg/m3 0.6 mg/m3
1319-77-3 Cresol, all isomers 5 ppm 10 ppm Skin
4170-30-3 Crotonaldehyde **C 0.3 ppm Skin
299-86-5 Crufomate 5 mg/m3 10 mg/m3
98-82-8 Cumene 50 ppm 74 ppm
420-04-2 Cyanamide 2 mg/m3 4 mg/m3
460-19-5 Cyanogen 10 ppm 15 ppm
506-77-4 Cyanogen chloride **C0.3 ppm
110-82-7 Cyclohexane 100 ppm 150 ppm
108-93-0 Cyclohexanol 50 ppm 62 ppm Skin
108-94-1 Cyclohexanone 20 ppm 50 ppm Skin
110-83-8 Cyclohexene 300 ppm 375 ppm
108-91-8 Cyclohexylamine 10 ppm 15 ppm
121-82-4 Cyclonite (RDX) 0.5 mg/m3 1.5 mg/m3 Skin
542-92-7 Cyclopentadiene 75 ppm 94 ppm
287-92-3 Cyclopentane 600 ppm 900 ppm
13121-70-5 Cyhexatin 5 mg/m3 10 mg/m3
94-75-7 2,4-D (2,4-Dichlorophenoxy-acetic acid) 10 mg/m3 20 mg/m3
50-29-3 DDT (Dichlorodiphenyltrichloroethane) 1 mg/m3 3 mg/m3 T20
17702-41-9 Decaborane 0.05 ppm 0.15 ppm Skin
8065-48-3 Demeton (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin
919-86-8 Demeton-S-methyl, (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin, SEN
123-42-2 Diacetone alcohol (4-hydroxy-4- methyl-2-pentanone) 50 ppm 60 ppm

Contamination Limits/ cont'd

CAS Number Substance 8 hour average contamination limit mg/m³* or ppm* 15 minute average contamination limit mg/m³* or ppm* Notation+
333-41-5 Diazinon, (inhalable fraction++ and vapour) 0.01 mg/m3 0.03 mg/m3 Skin
334-88-3 Diazomethane 0.2 ppm 0.6 ppm T20
19287-45-7 Diborane 0.1 ppm 0.3 ppm
102-81-8 2-N-Dibutylaminoethanol 0.5 ppm 1 ppm Skin
2528-36-1 Dibutyl phenyl phosphate 0.3 ppm 0.6 ppm Skin
107-66-4 Dibutyl phosphate 1 ppm 2 ppm
84-74-2 Dibutyl phthalate 5 mg/m3 10 mg/m3
79-43-6 Dichloroacetic acid 0.5 ppm 1.5 ppm Skin, T20
7572-29-4 Dichloracetylene **C0.1 ppm
95-50-1 o-Dichlorobenzene 25 ppm 50 ppm
106-46-7 p-Dichlorobenzene 10 ppm 15 ppm T20
764-41-0 1,4-Dichloro-2-butene 0.005 ppm 0.015 ppm Skin, T20
75-71-8 Dichlorodifluoromethane 1000 ppm 1250 ppm
118-52-5 1,3-Dichloro-5, 5-dimethyl hydantoin 0.2 mg/m3 0.4 mg/m3
75-34-3 1,1-Dichloroethane 100 ppm 125 ppm
540-59-0; 156-59-2; 156-60-5 1,2-Dichloroethylene, all isomers 200 ppm 250 ppm
111-44-4 Dichloroethyl ether 5 ppm 10 ppm Skin
75-43-4 Dichlorofluoromethane 10 ppm 15 ppm
75-09-2 Dichloromethane 50 ppm 75 ppm T20
594-72-9 1,1-Dichloro-1-nitroethane 2 ppm 4 ppm
542-75-6 1,3-Dichloropropene 1 ppm 2 ppm Skin, T20
75-99-0 2,2-Dichloropropionic acid, (inhalable fraction++) 5 mg/m3 10 mg/m3
76-14-2 Dichlorotetrafluoroethane 1000 ppm 1250 ppm
62-73-7 Dichlorvos (DDVP), (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3 Skin, SEN, T20
141-66-2 Dicrotophos, (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin
77-73-6 Dicyclopentadiene 5 ppm 8 ppm
102-54-5 Dicyclopentadienyl iron 10 mg/m3 20 mg/m3
60-57-1 Dieldrin 0.25 mg/m3 0.75 mg/m3 Skin
683334-30-5; 68476-30-2; 68476-31-3; 68476-34-6; 77650-28-3 Diesel fuel as total hydrocarbons, (vapour) 100 mg/m3 150 mg/m3 Skin
111-42-2 Diethanolamine 2 mg/m3 4 mg/m3 Skin
109-89-7 Diethylamine 5 ppm 15 ppm Skin
100-37-8 2-Diethylaminoethanol 2 ppm 4 ppm Skin
111-40-0 Diethylene triamine 1 ppm 2 ppm Skin
96-22-0 Diethyl ketone 200 ppm 300 ppm
84-66-2 Diethyl phthalate 5 mg/m3 10 mg/m3
75-61-6 Difluorodibromomethane 100 ppm 125 ppm
2238-07-5 Diglycidyl ether (DGE) 0.1 ppm 0.3 ppm
108-83-8 Diisobutyl ketone 25 ppm 30 ppm
108-18-9 Diisopropylamine 5 ppm 7 ppm Skin
127-19-5 N,N-Dimethylacetamide 10 ppm 15 ppm Skin
124-40-3 Dimethylamine 5 ppm 15 ppm
121-69-7 Dimethylaniline (N,N-Dimethylaniline) 5 ppm 10 ppm Skin
14857-34-2 Dimethylethoxysilane 0.5 ppm 1.5 ppm
68-12-2 Dimethylformamide 10 ppm 15 ppm Skin, T20
57-14-7 1,1-Dimethylhydrazine 0.01 ppm 0.03 ppm Skin, T20
131-11-3 Dimethylphthalate 5 mg/m3 10 mg/m3
77-78-1 Dimethyl sulphate 0.1 ppm 0.3 ppm Skin, T20
75-18-3 Dimethyl sulphide 10 ppm 20 ppm
148-01-6 Dinitolmide 5 mg/m3 10 mg/m3
528-29-0; 99-65-0; 100-25-4; 25154-54-5 Dinitrobenzene (all isomers) 0.15 ppm 0.30 ppm Skin
534-52-1 Dinitro-o-cresol 0.2 mg/m3 0.6 mg/m3 Skin
25321-14-6 Dinitrotoluene 0.2 mg/m3 0.6 mg/m3 Skin, T20
123-91-1 1,4-Dioxane 20 ppm 30 ppm Skin, T20
78-34-2 Dioxathion (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3 Skin
646-06-0 1,3-Dioxolane 20 ppm 30 ppm
122-39-4 Diphenylamine 10 mg/m3 20 mg/m3
34590-94-8 Dipropylene glycol methyl ether (DPGME) 100 ppm 150 ppm Skin
123-19-3 Dipropyl ketone 50 ppm 60 ppm
2764-72-9; Diquat:
85-00-7; (inhalable fraction++) 0.5 mg/m3 1.5 mg/m3 Skin
6385-62-2 (respirable fraction++) 0.1 mg/m3 0.3 mg/m3 Skin
117-81-7 Di-sec, octyl phthalate (Di-2- ethylhexyl phthalate or DEHP) 5 mg/m3 10 mg/m3 T20
97-77-8 Disulphiram 2 mg/m3 4 mg/m3
298-04-4 Disulphoton, (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin
128-37-0 2,6-Di-tert-butyl-p-cresol (butylated hydroxytoluene or BHT) (inhalable fraction++ and vapour) 2 mg/m3 4 mg/m3
330-54-1 Diuron 10 mg/m3 20 mg/m3
1321-74-0 Divinyl benzene 10 ppm 15 ppm
112-55-0 Dodecyl mercaptan 0.1 ppm 0.3 ppm SEN
1302-74-5 Emery 10 mg/m3 20 mg/m3
115-29-7 Endosulphan 0.1 mg/m3 0.3 mg/m3 Skin
72-20-8 Endrin 0.1 mg/m3 0.3 mg/m3 Skin
13838-16-9 Enflurane 75 ppm 100 ppm
106-89-8 Epichlorohydrin 0.5 ppm 1.5 ppm Skin, T20
2104-64-5 EPN (inhalable fraction++) 0.1 mg/m3 0.3 mg/m3 Skin
74-84-0 Ethane See Aliphatic hydrocarbon gases [C1-C4]
64-17-5 Ethanol 1000 ppm 1250 ppm
141-43-5 Ethanolamine 3 ppm 6 ppm
563-12-2 Ethion, (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin
110-80-5 2-Ethoxyethanol (Glycol monoethyl ether) 5 ppm 7 ppm Skin
111-15-9 2-Ethyoxyethyl acetate (Cellosolve acetate) 5 ppm 8 ppm Skin
141-78-6 Ethyl acetate 400 ppm 500 ppm
140-88-5 Ethyl acrylate 5 ppm 15 ppm T20
75-04-7 Ethylamine 5 ppm 15 ppm Skin
541-85-5 Ethyl amyl ketone (5-Methyl-3- heptanone) 25 ppm 30 ppm
100-41-4 Ethyl benzene 100 ppm 125 ppm T20
74-96-4 Ethyl bromide 5 ppm 7 ppm Skin
637-92-3 Ethyl tert-butyl ether 5 ppm 10 ppm
106-35-4 Ethyl butyl ketone (3-Heptanone) 50 ppm 75 ppm
75-00-3 Ethyl chloride 100 ppm 125 ppm Skin
7085-85-0 Ethyl cyanoacrylate 0.2 ppm 0.6 ppm
74-85-1 Ethylene 200 ppm 250 ppm
107-15-3 Ethylenediamine 10 ppm 15 ppm Skin
107-06-2 Ethylene dichloride 10 ppm 20 ppm
107-21-1 Ethylene glycol, (as an aerosol) **C 100 mg/m3
628-96-6 Ethylene glycol dinitrate (EGDN) 0.05 ppm 0.15 ppm Skin
75-21-8 Ethylene oxide 1 ppm 2 ppm T20
151-56-4 Ethylenimine 0.5 ppm 1.5 ppm Skin, T20
60-29-7 Ethyl ether 400 ppm 500 ppm
109-94-4 Ethyl formate 100 ppm 150 ppm
149-57-5 2-Ethylhexanoic acid, (inhalable fraction++ and vapour) 5 mg/m3 10 mg/m3
16219-75-3 Ethylidene norbornene **C5 ppm
75-08-1 Ethyl mercaptan 0.5 ppm 1.5 ppm
100-74-3 N-Ethylmorpholine 5 ppm 8 ppm Skin
78-10-4 Ethyl silicate 10 ppm 15 ppm
22224-92-6 Fenamiphos 0.1 mg/m3 0.3 mg/m3 Skin
115-90-2 Fensulphothion (inhalable fraction++ and vapour) 0.01 mg/m3 0.03 mg/m3 Skin
55-38-9 Fenthion 0.2 mg/m3 0.6 mg/m3 Skin
14484-64-1 Ferbam 10 mg/m3 20 mg/m3
12604-58-9 Ferrovanadium dust 1 mg/m3 3 mg/m3
Flour dust 3 mg/m3 6 mg/m3 SEN
------- Fluoride, (as F) 2.5 mg/m3 5 mg/m3
7782-41-4 Fluorine 1 ppm 2 ppm
944-22-9 Fonofos 0.1 mg/m3 0.3 mg/m3 Skin
50-00-0 Formaldehyde **C0.3 ppm SEN, T20
75-12-7 Formamide 10 ppm 15 ppm Skin
64-18-6 Formic acid 5 ppm 10 ppm
98-01-1 Furfural 2 ppm 4 ppm Skin
98-00-0 Furfuryl alcohol 10 ppm 15 ppm Skin
1303-00-0 Gallium arsenide (respirable fraction++) 0.0003 mg/m3 0.0009 mg/m3
86290-81-5 Gasoline 300 ppm 500 ppm
7782-65-2 Germanium tetrahydride 0.2 ppm 0.6 ppm
111-30-8 Glutaraldehyde, activated and inactivated **C0.05 ppm SEN
56-81-5 Glycerin mist 10 mg/m3 20 mg/m3
556-52-5 Glycidol 2 ppm 4 ppm
107-22-2 Glyoxal, (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3 SEN
------- Grain dust (oat, wheat, barley) 4 mg/m3 8 mg/m3
7782-42-5 Graphite, natural-all forms except graphite fibres (respirable fraction++) 2 mg/m3 4 mg/m3
7778-18-9 Gypsum (Calcium sulphate) 10 mg/m3 20 mg/m3
7440-58-6 Hafnium and compounds, (as Hf) 0.5 mg/m3 1.5 mg/m3
151-67-7 Halothane 50 ppm 60 ppm
76-44-8; 1024-57-3 Heptachlor and Heptchlor epoxide 0.05 mg/m3 0.15 mg/m3 Skin, T20
142-82-5 Heptane (n-Heptane) 400 ppm 500 ppm
118-74-1 Hexachlorobenzene 0.002 mg/m3 0.006 mg/m3 Skin, T20
87-68-3 Hexachlorobutadiene 0.02 ppm 0.06 ppm Skin, T20
77-47-4 Hexachlorocyclopentadiene 0.01 ppm 0.03 ppm
67-72-1 Hexachloroethane 1 ppm 2 ppm Skin, T20
1335-87-1 Hexachloronaphthalene 0.2 mg/m3 0.6 mg/m3 Skin
684-16-2 Hexafluoroacetone 0.1 ppm 0.3 ppm Skin
85-42-7; 13149-00-3; 14166-21-3 Hexahydrophthalic anhydride, (inhalable fraction++ and vapour), all isomers **C0.005 mg/m3 SEN
822-06-0 Hexamethylene diisocyanate 0.005 ppm 0.015 ppm
110-54-3 Hexane (n-Hexane) 50 ppm 62.5 ppm Skin
---------- Hexane (other isomers) 500 ppm 1000 ppm
124-09-4 Hexanediamine 0.5 ppm 1.0 ppm
592-41-6 1-Hexene 50 ppm 75 ppm
108-84-9 sec-Hexyl acetate 50 ppm 60 ppm
107-41-5 Hexylene glycol **C25 ppm
302-01-2 Hydrazine 0.01 ppm 0.03 ppm Skin, T20
61788-32-7 Hydrogenated terphenyls (nonirradiated) 0.5 ppm 1.5 ppm
10035-10-6 Hydrogen bromide **C2 ppm
7647-01-0 Hydrogen chloride **C2 ppm
Hydrogen cyanide and cyanide salts, (as CN):
74-90-8 Hydrogen cyanide **C4.7 ppm Skin
592-01-8; 151-50-8; 143-33-9 Cyanide salts **C 5 mg/m3 Skin
7664-39-3 Hydrogen fluoride, (as F) 0.5 ppm **C 2 ppm

Contamination Limits / cont'd

CAS Number Substance 8 hour average contamination limit mg/m³* or ppm* 15 minute average contamination limit mg/m³* or ppm* Notation+
7722-84-1 Hydrogen peroxide 1 ppm 2 ppm
7783-07-5 Hydrogen selenide, (as Se) 0.05 ppm 0.15 ppm
7783-06-4 Hydrogen sulphide 10 ppm 15 ppm
123-31-9 Hydroquinone 2 mg/m3 4 mg/m3
999-61-1 2-Hydroxypropyl acrylate 0.5 ppm 1 ppm Skin, SEN
95-13-6 Indene 10 ppm 15 ppm
7440-74-6 Indium and Compounds, (as In) 0.1 mg/m3 0.3 mg/m3 T20 (Indium pho-sphide)
7553-56-2 Iodine **C0.1 ppm
75-47-8 Iodoform 0.6 ppm 1.2 ppm
1309-37-1 Iron oxide fume, (dust and fume) (Fe2O3, as Fe) 5 mg/m3 10 mg/m3
13463-40-6 Iron pentacarbonyl, (as Fe) 0.1 ppm 0.2 ppm
---------- Iron salts, soluble, (as Fe) 1 mg/m3 3 mg/m3
123-51-3 Isoamyl alcohol 100 ppm 125 ppm
110-19-0 Isobutyl acetate 150 ppm 188 ppm
78-83-1 Isobutyl alcohol 50 ppm 60 ppm
542-56-3 Isobutyl nitrite, (inhalable fraction++ and vapour) **C1 ppm
26952-21-6 Isooctyl alcohol 50 ppm 60 ppm Skin
78-59-1 Isophorone **C5 ppm
4098-71-9 Isophorone diisocyanate 0.005 ppm 0.015 ppm
109-59-1 2-Isopropoxyethanol 25 ppm 38 ppm Skin
108-21-4 Isopropyl acetate 100 ppm 200 ppm
67-63-0 Isopropyl alcohol 200 ppm 400 ppm
75-31-0 Isopropylamine 5 ppm 10 ppm
768-52-5 N-Isopropylaniline 2 ppm 4 ppm Skin
108-20-3 Isopropyl ether 250 ppm 310 ppm
4016-14-2 Isopropyl glycidyl ether (IGE) 50 ppm 75 ppm
1332-58-7 Kaolin (respirable fraction++) 2 mg/m3 4 mg/m3
8008-20-6; 64742-81-0 Kerosene /Jet fuels, as total hydrocarbon vapour 200 mg/m3 250 mg/m3 Skin
463-51-4 Ketene 0.5 ppm 1.5 ppm
7439-92-1 Lead and inorganic compounds, (as Pb) 0.05 mg/m3 0.15 mg/m3 T20
3687-31-8 Lead arsenate, (as Pb3(AsO4)2) 0.15 mg/m3 0.45 mg/m3
7758-97-6 Lead chromate, (as Pb) 0.05 mg/m3 0.15 mg/m3 T20
7758-97-6 Lead chromate, (as Cr) 0.012 mg/m3 0.036 mg/m3 T20
1317-65-3; 471-34-1 Limestone (calcium carbonate) 10 mg/m3 20 mg/m3
58-89-9 Lindane 0.5 mg/m3 1.5 mg/m3 Skin
7580-67-8 Lithium hydride 0.025 mg/m3 0.075 mg/m3
68476-85-7 L.P.G. (liquified petroleum gas) See Aliphatic hydrocarbon gases [C1-C4]
546-93-0 Magnesite 10 mg/m3 20 mg/m3
1309-48-4 Magnesium oxide (inhalable fraction++) 10 mg/m3 20 mg/m3
121-75-5 Malathion, (inhalable fraction++ and vapour) 1 mg/m3 3 mg/m3 Skin
108-31-6 Maleic anhydride 0.1 ppm 0.3 ppm SEN
7439-96-5 Manganese and inorganic compounds, (as Mn) 0.2 mg/m3 0.6 mg/m3
12079-65-1 Manganese cyclopentadienyl tricarbonyl, (as Mn) 0.1 mg/m3 0.3 mg/m3 Skin
7439-97-6 Mercury, (as Hg):
Alkyl compounds 0.01 mg/m3 0.03 mg/m3 Skin
Aryl compounds 0.1 mg/m3 0.3 mg/m3 Skin
Inorganic forms, including metallic mercury 0.025 mg/m3 0.075 mg/m3 Skin
141-79-7 Mesityl oxide 15 ppm 25 ppm
79-41-4 Methacrylic acid 20 ppm 30 ppm
74-82-8 Methane See Aliphatic hydrocarbon gases [C1-C4]
16752-77-5 Methomyl 2.5 mg/m3 5 mg/m3
72-43-5 Methoxychlor 10 mg/m3 20 mg/m3
109-86-4 2-Methoxyethanol (Methylcellosolve-EGME) 5 ppm 8 ppm Skin
110-49-6 2-Methoxyethyl acetate (Methyl cellosolve acetate-EGMEA) 5 ppm 8 ppm Skin
150-76-5 4-Methoxyphenol 5 mg/m3 10 mg/m3
79-20-9 Methyl acetate 200 ppm 250 ppm
74-99-7 Methyl acetylene 1000 ppm 1250 ppm
59355-75-8 Methyl acetylene-propadiene mixture (MAPP) 1000 ppm 1250 ppm
96-33-3 Methyl acrylate 2 ppm 4 ppm Skin, SEN
126-98-7 Methylacrylonitrile 1 ppm 2 ppm Skin
109-87-5 Methylal (dimethoxy methane) 1000 ppm 1250 ppm
67-56-1 Methyl alcohol (methanol) 200 ppm 250 ppm Skin
74-89-5 Methylamine 5 ppm 15 ppm
110-43-0 Methyl n-amyl ketone (2-Heptanone) 50 ppm 60 ppm
100-61-8 N-Methylaniline 0.5 ppm 1 ppm Skin
74-83-9 Methyl bromide 1 ppm 3 ppm Skin
1634-04-4 Methyl tert-butyl ether (MTBE) 50 ppm 75 ppm
591-78-6 Methyl n-butyl ketone 5 ppm 10 ppm Skin
74-87-3 Methyl chloride 50 ppm 100 ppm Skin
137-05-3 Methyl 2-cyanoacrylate 0.2 ppm 0.6 ppm
108-87-2 Methylcyclohexane 400 ppm 500 ppm
25639-42-3 Methylcyclohexanol 50 ppm 60 ppm
583-60-8 o-Methylcyclohexanone 50 ppm 75 ppm Skin
12108-13-3 2-Methylcyclopentadienyl manganese tricarbonyl, (as Mn) 0.2 mg/m3 0.6 mg/m3 Skin
8022-00-2 Methyl demeton 0.5 mg/m3 1.5 mg/m3 Skin
101-68-8 Methylene bisphenyl isocyanate (MDI) 0.005 ppm 0.015 ppm
101-14-4 4,4'-Methylene bis (2-chloroaniline) (MBOCA, MOCA) 0.01 ppm 0.03 ppm Skin, T20
5124-30-1 Methylene bis (4-cyclohexylisocyanate) 0.005 ppm 0.015 ppm
75-09-2 Methylene choride (dichloromethane) 50 ppm 63 ppm
101-77-9 4,4'-Methylene dianiline 0.1 ppm 0.3 ppm Skin, T20
78-93-3 Methyl ethyl ketone (MEK) 200 ppm 300 ppm
1338-23-4 Methyl ethyl ketone peroxide **C0.2 ppm
107-31-3 Methyl formate 100 ppm 150 ppm
60-34-4 Methyl hydrazine 0.01 ppm 0.03 ppm Skin, T20
74-88-4 Methyl iodide 2 ppm 4 ppm Skin, T20
110-12-3 Methyl isoamyl ketone 50 ppm 60 ppm
108-11-2 Methyl isobutyl carbinol 25 ppm 40 ppm Skin
108-10-1 Methyl isobutyl ketone 50 ppm 75 ppm
624-83-9 Methyl isocyanate 0.02 ppm 0.06 ppm Skin
563-80-4 Methyl isopropyl ketone 200 ppm 250 ppm
74-93-1 Methyl mercaptan 0.5 ppm 1.5 ppm
80-62-6 Methyl methacrylate 50 ppm 100 ppm SEN
298-00-0 Methyl parathion 0.2 mg/m3 0.6 mg/m3 Skin
107-87-9 Methyl propyl ketone 200 ppm 250 ppm
681-84-5 Methyl silicate 1 ppm 2 ppm
98-83-9 alpha-Methyl styrene 50 ppm 100 ppm
78-94-4 Methyl vinyl ketone **C0.2 ppm Skin, SEN
21087-64-9 Metribuzin 5 mg/m3 10 mg/m3
7786-34-7 Mevinphos (inhalable fraction++ and vapour) 0.01mg/m3 0.03 mg/m3 Skin
12001-26-2 Mica (respirable fraction++) 3 mg/m3 6 mg/m3
7439-98-7 Molybdenum, (as Mo):
Soluble compounds, (respirable fraction++) 0.5 mg/m3 1.5 mg/m3
Metal and insoluble compounds, (inhalable fraction++) 10 mg/m3 20 mg/m3
Metal and insoluble compounds, (respirable fraction++) 3 mg/m3 6 mg/m3
6923-22-4 Monocrotophos (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin
110-91-8 Morpholine 20 ppm 30 ppm Skin
300-76-5 Naled, (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3 Skin, SEN
91-20-3 Naphthalene 10 ppm 15 ppm Skin
8006-14-2 Natural gas See Aliphatic hydrocarbon gases: Alkane [C1-C4]
9006-04-6 Natural rubber latex (as total proteins), (inhalable fraction++) 0.001 mg/m3 0.003 mg/m3 Skin, SEN
7440-02-0 Nickel, (as Ni):
Elemental (inhalable fraction++) 1.5 mg/m3 3 mg/m3 T20
Soluble inorganic compounds, (not otherwise specified) (inhalable fraction++) 0.1 mg/m3 0.3 mg/m3
Insoluble inorganic, (as not otherwise specified) (inhalable fraction++) 0.2 mg/m3 0.6 mg/m3
12035-72-2 Nickel subsulphide, (as Ni), (inhalable fraction++) 0.1 mg/m3 0.3 mg/m3 T20
13463-39-3 Nickel carbonyl, (as Ni) 0.05 ppm 0.15 ppm
54-11-5 Nicotine 0.5 mg/m3 1.5 mg/m3 Skin
1929-82-4 Nitrapyrin 10 mg/m3 20 mg/m3
7697-37-2 Nitric acid 2 ppm 4 ppm
10102-43-9 Nitric oxide 25 ppm 38 ppm
100-01-6 p-Nitroaniline 3 mg/m3 6 mg/m3 Skin
98-95-3 Nitrobenzene 1 ppm 2 ppm Skin
100-00-5 p-Nitrochlorobenzene 0.1 ppm 0.3 ppm Skin
79-24-3 Nitroethane 100 ppm 125 ppm
10102-44-0 Nitrogen dioxide 3 ppm 5 ppm
7783-54-2 Nitrogen trifluoride 10 ppm 20 ppm
55-63-0 Nitroglycerin (NG) 0.05 ppm 0.15 ppm Skin
75-52-5 Nitromethane 20 ppm 30 ppm
108-03-2 1-Nitropropane 25 ppm 40 ppm
79-46-9 2-Nitropropane 10 ppm 20 ppm T20
88-72-2; 99-08-1; 99-99-0 Nitrotoluene isomers 2 ppm 3 ppm Skin
10024-97-2 Nitrous oxide 50 ppm 75 ppm
111-84-2 Nonane, all isomers 200 ppm 250 ppm
2234-13-1 Octachloronaphthalene 0.1 mg/m3 0.3 mg/m3 Skin
111-65-9 Octane, all isomers 300 ppm 375 ppm
8012-95-1 Oil mist, mineral 5 mg/m3 10 mg/m3
20816-12-0 Osmium tetroxide, (as Os) 0.0002 ppm 0.0006 ppm
144-62-7 Oxalic acid 1 mg/m3 2 mg/m3
80-51-3 p,p'-Oxybis(benzenesulphonyl hydrazide), (inhalable fraction++) 0.1 mg/m3 0.3 mg/m3
7783-41-7 Oxygen difluoride **C0.05 ppm
10028-15-6 Ozone 0.05 ppm 0.15 ppm
8002-74-2 Paraffin wax fume 2 mg/m3 4 mg/m3
4685-14-7 Paraquat, total dust 0.5 mg/m3 1.5 mg/m3
Paraquat, (respirable fraction++) 0.1 mg/m3 0.3 mg/m3
56-38-2 Parathion, (inhalable fraction++ and vapour) 0.05 mg/m3 0.15 mg/m3 Skin
----- Particulate polycyclic aromatic hydrocarbons (PPAH), as benzene solubles, See Coal tar pitch volatiles 0.2 mg/m3 0.6 mg/m3 T20
----- Particles (Insoluble or Poorly Soluble) Not Otherwise Specified:
Inhalable fraction++ 10 mg/m3 20 mg/m3
Respirable fraction++ 3 mg/m3 6 mg/m3
19624-22-7 Pentaborane 0.005 ppm 0.015 ppm
1321-64-8 Pentachloronaphthalene 0.5 mg/m3 1.5 mg/m3 Skin
82-68-8 Pentachloronitrobenzene 0.5 mg/m3 1.5 mg/m3
87-86-5 Pentachlorophenol 0.5 mg/m3 1.5 mg/m3 Skin
115-77-5 Pentaerythritol 10 mg/m3 20 mg/m3
78-78-4; 109-66-0; 463-82-1 Pentane, all isomers 600 ppm 750 ppm

Contamination Limits...cont'd

CAS Number Substance 8 hour average contamination limit mg/m³* or ppm* 15 minute average contamination limit mg/m³* or ppm* Notation+
628-63-7; 626-38-0; 123-92-2; 625-16-1; 624-41-9; 620-11-1 Pentyl acetate, all isomers 50 ppm 100 ppm
594-42-3 Perchloromethyl mercaptan 0.1 ppm 0.3 ppm
7616-94-6 Perchloryl fluoride 3 ppm 6 ppm
19430-93-4 Perfluorobutyl ethylene 100 ppm 150 ppm
382-21-8 Perfluoroisobutylene **C0.01 ppm
93763-70-3 Perlite 10 mg/m3 20 mg/m3
Persulphates, as persulphate 0.1 mg/m3 0.3 mg/m3
108-95-2 Phenol 5 ppm 7.5 ppm Skin
92-84-2 Phenothiazine 5 mg/m3 10 mg/m3 Skin
95-54-5; 108-45-2; 106-50-3 Phenylene diamine isomers 0.1 mg/m3 0.3 mg/m3
101-84-8 Phenyl ether (vapour) 1 ppm 2 ppm
122-60-1 Phenyl glycidyl ether (PGE) 0.1 ppm 0.3 ppm Skin, SEN, T20
100-63-0 Phenyl hydrazine 0.1 ppm 0.3 ppm Skin, T20
108-98-5 Phenyl mercaptan 0.1 ppm 0.3 ppm Skin
638-21-1 Phenylphosphine **C0.05 ppm
298-02-2 Phorate (inhalable fraction++ and vapour) 0.05 mg/m3 0.2 mg/m3 Skin
75-44-5 Phosgene (Carbonyl chloride) 0.1 ppm 0.3 ppm
7803-51-2 Phosphine 0.3 ppm 1 ppm
7664-38-2 Phosphoric acid 1 mg/m3 3 mg/m3
12185-10-3 Phosphorus (yellow) 0.1 mg/m3 0.3 mg/m3
10025-87-3 Phosphorous oxychloride 0.1 ppm 0.3 ppm
10026-13-8 Phosphorous pentachloride 0.1 ppm 0.3 ppm
1314-80-3 Phosphorous pentasulphide 1 mg/m3 3 mg/m3
7719-12-2 Phosphorous trichloride 0.2 ppm 0.5 ppm
85-44-9 Phthalic anhydride 1 ppm 2 ppm SEN
626-17-5 m-Phthalodinitrile 5 mg/m3 10 mg/m3
1918-02-1 Picloram 10 mg/m3 20 mg/m3
88-89-1 Picric acid 0.1 mg/m3 0.3 mg/m3
83-26-1 Pindone 0.1 mg/m3 0.3 mg/m3
142-64-3 Piperazine dihydrochloride 5 mg/m3 10 mg/m3
7778-18-9 Plaster of Paris (Calcium sulphate) 10 mg/m3 20 mg/m3
7440-06-4 Platinum:
metal 1 mg/m3 3 mg/m3
soluble salt, (as Pt) 0.002 mg/m3 0.006 mg/m3
65997-15-1 Portland cement 10 mg/m3 20 mg/m3
1310-58-3 Potassium hydroxide **C2 mg/m3
74-98-6 Propane See Aliphatic hydrocarbon gases [C1-C4]
107-19-7 Propargyl alcohol 1 ppm 3 ppm Skin
57-57-8 beta-Propriolactone 0.5 ppm 1 ppm T20
123-38-6 Propionaldehyde 20 ppm 30 ppm
79-09-4 Propionic acid 10 ppm 15 ppm
114-26-1 Propoxur 0.5 mg/m3 1.5 mg/m3
109-60-4 n-Propyl acetate 200 ppm 250 ppm
71-23-8 Propyl alcohol (n-propanol) 200 ppm 400 ppm
78-87-5 Propylene dichloride 75 ppm 110 ppm
6423-43-4 Propylene glycol dinitrate 0.05 ppm 0.15 ppm Skin
107-98-2 Propylene glycol monomethyl ether (PGME or 1-methoxy-2-propanol) 100 ppm 150 ppm
75-56-9 Propylene oxide 2 ppm 4 ppm SEN, T20
75-55-8 Propylenimine 2 ppm 4 ppm Skin, T20
627-13-4 n-Propyl nitrate 25 ppm 40 ppm
8003-34-7 Pyrethrum 5 mg/m3 10 mg/m3
110-86-1 Pyridine 1 ppm 3 ppm
106-51-4 Quinone 0.1 ppm 0.3 ppm
108-46-3 Resorcinol 10 ppm 20 ppm
7440-16-6 Rhodium, (as Rh):
Metal and insoluble compounds 1 mg/m3 3 mg/m3
Soluble compounds 0.01 mg/m3 0.03 mg/m3
299-84-3 Ronnel 10 mg/m3 20 mg/m3
83-79-4 Rotenone (commercial) 5 mg/m3 10 mg/m3
----- Rouge 10 mg/m3 20 mg/m3
8030-30-6 Rubber solvent (Naphtha) 400 ppm 500 ppm
7782-49-2 Selenium and compounds, (as Se) 0.2 mg/m3 0.6 mg/m3
7783-79-1 Selenium hexafluoride, (as Se) 0.05 ppm 0.15 ppm
136-78-7 Sesone 10 mg/m3 20 mg/m3
Silica Amorphous:
61790-53-2 Diatomaceous earth (uncalcined) (inhalable fraction ++) 10 mg/m3 20 mg/m3
61790-53-2 Diatomaceous earth (uncalcined) (respirable fraction ++) 3 mg/m3 6 mg/m3
112926-00-8 Precipitated silica and silica gel 10 mg/m3 20 mg/m3
69012-46-2 Silica, fume (respirable fraction++) 2 mg/m3
60676-86-0 Silica, fused (respirable fraction++) 0.1 mg/m3
Silica - Crystalline#:
14464-46-1 Cristobalite (respirable fraction++) 0.05 mg/m3
14808-60-7 Quartz (respirable fraction++) 0.05 mg/m3 T20
1317-95-9 Tripoli, as quartz (respirable fraction++) 0.1 mg/m3
7440-21-3 Silicon 10 mg/m3 20 mg/m3
409-21-2 Silicon Carbide
Nonfibrous, (inhalable fraction++) 10 mg/m3 20 mg/m3
Nonfibrous, (respirable fraction++) 3 mg/m3 6 mg/m3
Fibrous (including whiskers), (respirable fibres) 0.1 f/cc## T20
7803-62-5 Silicon tetrahydride (Silane) 5 ppm 10 ppm
7440-22-4 Silver, metal 0.1 mg/m3 0.3 mg/m3
----- Silver soluble compounds, (as Ag) 0.01 mg/m3 0.03 mg/m3
----- Soapstone (total dust) 6 mg/m3
----- Soapstone (respirable fraction++) 3 mg/m3 6 mg/m3
26628-22-8 Sodium azide:
as Sodium azide **C0.29 mg/m3
as Hydrazoic acid vapour **C0.11 ppm
7631-90-5 Sodium bisulphite 5 mg/m3 10 mg/m3
62-74-8 Sodium fluoroacetate 0.05 mg/m3 0.15 mg/m3 Skin
1310-73-2 Sodium hydroxide **C2 mg/m3
7681-57-4 Sodium metabisulphite 5 mg/m3 10 mg/m3
9005-25-8 Starch 10 mg/m3 20 mg/m3
----- Stearates 10 mg/m3 20 mg/m3
7803-52-3 Stibine (Antimony hydride) 0.1 ppm 0.3 ppm
8052-41-3 Stoddard solvent 100 ppm 125 ppm
7789-06-2 Strontium chromate, (as Cr) 0.0005 mg/m3 0.0015 mg/m3 T20
57-24-9 Strychnine 0.15 mg/m3 0.45 mg/m3
100-42-5 Styrene, monomer 20 ppm 40 ppm T20
1395-21-7; 9014-01-1 Subtilisins, (as crystalline active enzyme) **C0.00006 mg/m3
57-50-1 Sucrose 10 mg/m3 20 mg/m3
74222-97-2 Sulphometuron methyl 5 mg/m3 10 mg/m3
3689-24-5 Sulphotep (TEDP) (inhalable fraction++ and vapour) 0.1 mg/m3 0.3 mg/m3 Skin
7446-09-5 Sulphur dioxide 2 ppm 5 ppm
2551-62-4 Sulphur hexafluoride 1000 ppm 1250 ppm
7664-93-9 Sulphuric acid, (thoracic fraction++) 0.2 mg/m3 0.6 mg/m3 T20, strong acid mists only
10025-67-9 Sulphur monochloride **C1 ppm
5714-22-7 Sulphur pentafluoride **C0.01 ppm
7783-60-0 Sulphur tetrafluoride **C0.1 ppm
2699-79-8 Sulphuryl fluoride 5 ppm 10 ppm
35400-43-2 Sulprofos 1 mg/m3 3 mg/m3
Synthetic Vitreous Fibres:
Continous filament glass fibres, (respirable fibres) 1 f/cc## 3 f/cc
Continous filament glass fibres, (inhalable fraction++) 5 mg/m3 10 mg/m3
Glass wool fibres, (respirable fibres) 1 f/cc 3 f/cc
Rock wool fibres, (respirable fibres) 1 f/cc 3 f/cc
Slag wool fibres, (respirable fibres) 1 f/cc 3 f/cc
Special purpose glass fibres, (respirable fibres) 1 f/cc 3 f/cc
Refractory ceramic fibres, (respirable fibres) 0.2 f/cc T20
93-76-5 2,4,5-T 10 mg/m3 20 mg/m3
14807-96-6 Talc, (respirable fraction++) 2 mg/m3
7440-25-7 Tantalum metal and oxide, (as Ta) 5 mg/m3 10 mg/m3
7783-80-4 Tellurium hexafluoride, (as Te) 0.02 ppm 0.03 ppm
13494-80-9 Tellurium and other tellurium compounds, (as Te) excluding hydrogen telluride 0.1 mg/m3 0.3 mg/m3
3383-96-8 Temephos, (inhalable fraction++ and vapour) 1 mg/m3 3 mg/m3 Skin
13071-79-9 Terbufos, (inhalable fraction++ and vapour) 0.01 mg/m3 0.03 mg/m3 Skin
100-21-0 Terephthalic acid 10 mg/m3 20 mg/m3
26140-60-3 Terphenyls **C5 mg/m3
76-11-9 1,1,1,2-Tetrachloro-2, 2-difluoroethane 500 ppm 625 ppm
76-12-0 1,1,2,2-Tetrachloro-1, 2-difluoroethane 500 ppm 625 ppm
79-34-5 1,1,2,2-Tetrachloroethane 1 ppm 2 ppm Skin
127-18-4 Tetrachloroethylene (Perchloroethylene) 25 ppm 100 ppm T20
1335-88-2 Tetrachloronaphthalene 2 mg/m3 4 mg/m3
78-00-2 Tetraethyl lead, (as Pb) 0.1 mg/m3 0.3 mg/m3 Skin
107-49-3 Tetraethyl pyrophosphate (TEPP) 0.05 mg/m3 0.15 mg/m3 Skin
116-14-3 Tetrafluoroethylene 2 ppm 4 ppm T20

Contamination Limits...cont'd

CAS Number Substance 8 hour average contamination limit mg/m³* or ppm* 15 minute average contamination limit mg/m³* or ppm* Notation+
109-99-9 Tetrahydrofuran 50 ppm 100 ppm Skin
Tetrakis (hydroxymethyl) phosphonium salts:
124-64-1 Tetrakis (hydroxymethyl) phosphonium chloride 2 mg/m3 4 mg/m3
55566-30-8 Tetrakis (hydroxymethyl) phosphonium sulphate 2 mg/m3 4 mg/m3 SEN
75-74-1 Tetramethyl lead, (as Pb) 0.15 mg/m3 0.45 mg/m3 Skin
3333-52-6 Tetramethyl succinonitrile 0.5 ppm 1 ppm Skin
509-14-8 Tetranitromethane 0.005 ppm 0.015 ppm T20
7722-88-5 Tetrasodium pyrophosphate 5 mg/m3 10 mg/m3
479-45-8 Tetryl (2,4,6-trinitrophenyl-methyl nitramine) 1.5 mg/m3 3 mg/m3
7440-28-0 Thallium and soluble compounds, (as Tl) 0.1 mg/m3 0.3 mg/m3 Skin
96-69-5 4,4'-Thiobis (6-tert-butyl-m-cresol) 10 mg/m3 20 mg/m3
68-11-1 Thioglycolic acid 1 ppm 2 ppm Skin
7719-09-7 Thionyl chloride **C1 ppm
137-26-8 Thiram 1 mg/m3 3 mg/m3
7440-31-5 Tin, (as Sn):
metal 2 mg/m3 4 mg/m3
oxide and inorganic compounds except SnH4 2 mg/m3 4 mg/m3
organic compounds 0.1 mg/m3 0.2 mg/m3 Skin
13463-67-7 Titanium dioxide 10 mg/m3 20 mg/m3
108-88-3 Toluene (toluol) 50 ppm 60 ppm Skin
584-84-9; 91-08-7 Toluene-2,4- or 2,6-diisocyanate (TDI) 0.005 ppm 0.02 ppm SEN
95-53-4 o-Toluidine 2 ppm 4 ppm Skin, T20
108-44-1 m-Toluidine 2 ppm 4 ppm Skin
106-49-0 p-Toluidine 2 ppm 4 ppm Skin, T20
126-73-8 Tributyl phosphate 0.2 ppm 0.4 ppm
76-03-9 Trichloroacetic acid 1 ppm 2 ppm
120-82-1 1,2,4-Trichlorobenzene **C5 ppm
71-55-6 1,1,1-Trichloroethane 350 ppm 450 ppm
79-00-5 1,1,2-Trichloroethane 10 ppm 15 ppm Skin
79-01-6 Trichloroethylene 50 ppm 100 ppm
75-69-4 Trichlorofluoromethane **C1000 ppm
1321-65-9 Trichloronaphthalene 5 mg/m3 10 mg/m3 Skin
96-18-4 1,2,3-Trichloropropane 10 ppm 15 ppm Skin
76-13-1 1,1,2-Trichloro-1,2,2-trifluoroethane 1000 ppm 1250 ppm
52-68-6 Trichlorphon, (inhalable fraction++) 1 mg/m3 3 mg/m3
102-71-6 Triethanolamine 5 mg/m3 10 mg/m3
121-44-8 Triethylamine 1 ppm 3 ppm Skin
75-63-8 Trifluorobromomethane 1000 ppm 1200 ppm
2451-62-9 1,3,5-Triglycidyl-s-triazinetrione 0.05 mg/m3 0.15 mg/m3
552-30-7 Trimellitic anhydride **C0.04 mg/m3
75-50-3 Trimethylamine 5 ppm 15 ppm
25551-13-7 Trimethyl benzene (mixed isomer) 25 ppm 30 ppm
121-45-9 Trimethyl phosphite 2 ppm 4 ppm
118-96-7 2,4,6-Trinitrotoluene (TNT) 0.1 mg/m3 0.3 mg/m3 Skin
78-30-8 Triorthocresyl phosphate 0.1 mg/m3 0.3 mg/m3 Skin
603-34-9 Triphenylamine 5 mg/m3 10 mg/m3
115-86-6 Triphenyl phosphate 3 mg/m3 6 mg/m3
7440-33-7 Tungsten, (as W):
metal and insoluble compounds 5 mg/m3 10 mg/m3
soluble compounds 1 mg/m3 3 mg/m3
8006-64-2; 80-56-8; 127-91-3; 13466-78-9 Turpentine and selected monoterpenes 20 ppm 30 ppm SEN
7440-61-1 Uranium (natural)
Soluble and insoluble compounds, (as U) 0.2 mg/m3 0.6 mg/m3 T20
110-62-3 n-Valeraldehyde 50 ppm 60 ppm
1314-62-1 Vanadium pentoxide, as V2O5, dust and fume (respirable fraction++) 0.05 mg/m3 0.15 mg/m3
----- Vegetable oil mists 10 mg/m3 20 mg/m3
108-05-4 Vinyl acetate 10 ppm 15 ppm
593-60-2 Vinyl bromide 0.5 ppm 1.5 ppm T20
100-40-3 4-Vinyl cyclohexene 0.1 ppm 0.3 ppm T20
106-87-6 Vinyl cyclohexene dioxide 0.1 ppm 0.3 ppm Skin, T20
75-02-5 Vinyl fluoride 1 ppm 3 ppm T20
88-12-0 N-Vinyl-2-pyrrolidone 0.05 ppm 0.15 ppm
75-35-4 Vinylidene chloride 5 ppm 10 ppm
75-38-7 Vinyledene fluoride 500 ppm 625 ppm
25013-15-4 Vinyl toluene 50 ppm 100 ppm
8032-32-4 VM and P Naphtha 300 ppm 375 ppm
81-81-2 Warfarin 0.1 mg/m3 0.3 mg/m3
----- Welding fumes 5 mg/m3 10 mg/m3
Wood dust:
----- Softwoods 5 mg/m3 10 mg/m3 T20 (certain species), SEN* (certain species, see list at end of table)
----- Certain hardwoods such as beech and oak 1 mg/m3 3 mg/m3 T20 (certain species), SEN* (certain species, see list at end of table)
1330-20-7; 95-47-6; 108-38-3; 106-42-3 Xylene (o, m-, p-isomers) 100 ppm 150 ppm
1477-55-0 m-Xylene alpha, alpha'-diamine **C0.1 mg/m3 Skin
1300-73-8 Xylidine, mixed isomers (inhalable fraction++ and vapour) 0.5 ppm 1 ppm T20, Skin
7440-65-5 Yttrium metal and compounds, (as Y) 1 mg/m3 3 mg/m3
7646-85-7 Zinc chloride fume 1 mg/m3 2 mg/m3
13530-65-9; 11103-86-9; 37300-23-5 Zinc chromates, as Cr 0.01 mg/m3 0.03 mg/m3 T20
1314-13-2 Zinc oxide, fume and dust (respirable fraction++) 2 mg/m3 10 mg/m3
7440-67-7 Zirconium and compounds, (as Zr) 5 mg/m3 10 mg/m3

*mg/m3 - milligrams of substance per cubic metre of air; ppm - parts (volume) of substance per million parts (volume) of air

**C - ceiling limit.

Notes:

# - Trydimite removed

## - Fibres per cubic centimeter of air

+ - Explanation of Notations:

T20 - Substance is also In Table 20 and subject to Sections 306 and 311

Skin - Potentially harmful after absorption through the skin or mucous membranes

SEN - Well-demonstrated potential to produce sensitization

SEN* - Wood species suspected of inducing sensitization (see Table D)

Table A

Inhalable fraction:

For the application of this limit, inhalable fraction is that fraction of the aerosol that passes a size selector with the following characteristics:

Table A

Particle Aerodynamic Diameter (µm) Inhalable Particulate Mass (IPM) (%)
100
1 97
2 94
5 87
10 77
20 65
30 58
40 54.5
50 52.5
100 50

Table B

Respirable fraction:

For the application of this limit, respirable fraction is that fraction of the aerosol that passes a size selector with the following characteristics:

Table B

Particle Aerodynamic Diameter (µm) Respirable Particulate Mass (RPM) (%)
0 100
1 97
2 91
3 74
4 50
5 30
6 17
7 9
8 5
10 1

Table C

Thoracic fraction:

For the application of this limit, thoracic fraction is that fraction of the aerosol that passes a size selector with the following characteristics:

Particle Aerodynamic Diameter ( m) Particulate Mass

Table C

Particle Aerodynamic Diameter (µm) Thoracic Particulate Mass (TPM) (%)
0 100
2 94
4 89
6 80.5
8 67
10 50
12 35
14 23
16 15
18 9.5
20 6
25 2

Table D

Commercially Important Tree Species Suspected of Inducing Sensitization

Table D

Common Latin
SOFTWOODS
California redwood Sequoia sempervirens
Eastern white cedar Thuja occidentalis
Pine Pinus
Western red cedar Thuja plicata
HARDWOOD
Ash Fraxinus americana
Aspen/Poplar/Cottonwood Popilus
Beech Fagus
Oak Quercus
TROPICAL WOODS
Abirucana Pouteria
African zebra Microberlinia
Antiaris Antiaris africana Antiaris toxicara
Cabreuva Myrocarpus fastigiatus
Cedar of Lebanon Cedra libani
Central American walnut Juglans olanchana
Cocabolla Dalbergia retusa
African ebony Diospryos crassiflora
Fernam bouc Caesalpinia
Honduras rosewood Dalbergia stevensonii
Iroko or kambala Chlorophora excelsa
Kejaat Pterocarpus angolensis
Kotobe Nesorgordonia papaverifera
Limba Terminalia superba
Mahogany (African) Khaya spp.
Makore Tieghemella heckelii
Mansonia/Beté Mansonia altissima
Nara Pterocarpus indicus
Obeche/African maple/Samba Triplochiton scleroxylon
Palisander/Brazilian rosewood/ Tulip wood/Jakaranda Dalbergia nigra
Pau marfim Balfourdendron riedelianum
Ramin Gonystylus bancanus
Soapbark dust Quillaja saponaria
Spindle tree wood Euonymus europaeus
Tanganyike aningre

[Sask. Reg. 6/97, s. 14; 67/2007, s. 33]

Mines Regulations, 2003
R.R.S., c. O-1, r. 2

Part XIV Air Quality and Ventilation Underground at a Mine

Section 292 Airborne contaminants

292. (1) In this section, "uncombined silica" means silica that is not combined chemically with any other element or compound.

(2) An employer or contractor must take all reasonably practicable steps to minimize the dissemination of dust into any active mining area underground at a mine.

(3) Except as otherwise provided in these regulations, to the extent that is reasonably practicable, an employer or contractor must ensure that in any underground part of a mine where workers work or pass:

(a) the concentration of airborne carbon monoxide does not exceed 25 parts per million at any time;

(b) the concentration of airborne carbon dioxide does not exceed 5 000 parts per million at any time;

(c) the concentration of airborne nitrogen dioxide does not exceed two parts per million at any time; and

(d) the oxygen content is not less than 19.5% and not more than 23%, by volume at any time.

(4) If mining is carried out underground in strata containing uncombined silica in a crystalline form, an employer or contractor must:

(a) so far as is reasonably practicable, minimize the dissemination of dust into the general mine air during the construction, use and maintenance of every ore pass;

(b) provide an effective means to spray water within a suitable distance of the working face of every drift or raise to suppress any dust;

(c) ensure that the spray mentioned in clause (b) is used for a minimum of 15 minutes after any blasting operation is complete; and

(d) provide every drill with a water jet, spray or other suitable attachment to prevent dust from escaping and ensure that the attachment is used at all times during a drilling operation.