41 C.F.R. Subpart D—Gases, Vapors, Fumes, Dusts, and Mists
Title 41 - Public Contracts and Property Management
(a) (1) Exposures by inhalation, ingestion, skin absorption, or contact to any material or substance (i) at a concentration above those specified in the “Threshold Limit Values of Airborne Contaminants for 1968” of the American Conference of Governmental Industrial Hygienists, except for the ANSI Standards listed in Table I of this section and except for the values of mineral dusts listed in Table II of this section, and (ii) concentrations above those specified in Tables I and II of this section, shall be avoided, or protective equipment shall be provided and used. (2) The requirements of this section do not apply to exposures to airborne asbestos dust. Exposures of employees to airborne asbestos dust shall be subject to the requirements of 29 CFR 1910.93a. (b) To achieve compliance with paragraph (a) of this section, feasible administrative or engineering controls must first be determined and implemented in all cases. In cases where protective equipment in addition to other measures is used as the method of protecting the employee, such protection must be approved for each specific application by a competent industrial hygienist or other technically qualified source. [36 FR 23217, Dec. 7, 1971] Each contractor shall determine that compressed gas cylinders under his extent that this can be determined by visual inspection. Visual and other inspections shall be conducted as prescribed in the Hazardous Materials Regulations of the Department of Transportation (49 CFR Parts 171–179 and 14 CFR Part 103). Where those regulations are not applicable, visual and other inspections shall be conducted in accordance with Compressed Gas Association Pamphlets C–6–198 and C–8–1962. (a) The in-plant transfer, handling, storage, and utilization of acetylene in cylinders shall be in accordance with Compressed Gas Association Pamphlet G–1–1966. (b) The piped systems for the in-plant transfer and distribution of acetylene shall be designed, installed, maintained, and operated in accordance with Compressed Gas Association Pamphlet G–1.3–1959. (c) Plants for the generation of acetylene and the charging (filling) of acetylene cylinders shall be designed, constructed, and tested in accordance with the standards prescribed in Compressed Gas Association Pamphlet G–1.4–1966. The in-plant transfer, handling, storage, and utilization of oxygen as a liquid or a compressed gas shall be in accordance with Compressed Gas Association Pamphlet G–4–1962. The in-plant transfer, handling, storage, and utilization of hydrogen shall be in accordance with Compressed Gas Association Pamphlets G–5.1–1961 and G–5.2–1966. The piped systems for the in-plant transfer and distribution of nitrous oxide shall be designed, installed, maintained, and operated in accordance with Compressed Gas Association Pamphlet G–8.1–1964. The in-plant handling, storage, and utilization of all compressed gases in cylinders, portable tanks, rail tankcars, or motor vehicle cargo tanks shall be in accordance with Compressed Gas Association Pamphlet P–1–1965. [35 FR 1015, Jan. 24, 1970] Compressed gas cylinders, portable tanks, and cargo tanks shall have pressure relief devices installed and maintained in accordance with Compressed Gas Association Pamphlets S–1.1–1963 and 1965 addenda and S–1.2–1963. Welding or cutting, or both, on containers which have held flammable or combustible solids, liquids, or gases, or have contained substances which may produce flammable vapors or gases will not be attempted until the containers have been thoroughly cleaned, purged, or inerted in strict accordance with the rules and procedures embodied in American Welding Society Pamphlet A–6.0–65, edition of 1965. [35 FR 1015, Jan. 24, 1970]
Title 41: Public Contracts and Property Management
PART 50–204—SAFETY AND HEALTH STANDARDS FOR FEDERAL SUPPLY CONTRACTS
Subpart D—Gases, Vapors, Fumes, Dusts, and Mists
§ 50-204.50 Gases, vapors, fumes, dusts, and mists.
Table II_Mineral Dusts------------------------------------------------------------------------ Substance Mppcf\e\ Mg/M \3\------------------------------------------------------------------------Silica: Crystalline: Quartz (respirable)....................... 250\f\ 10mg/M \3\\m\ ------------------------- %SiO2=5 %SiO2=2 Quartz (total dust)....................... ........... 30mg/M \3\ ------------ ........... %SiO2=2 Cristobalite: Use \1/2\ the value calculated from the count or mass formulae for quartz. Tridymite: Use \1/2\ the value calculated from the formulae for quartz. Amorphous, including natural diatomaceous 20 80mg/M \3\ earth...................................... ------------ ........... %SiO2 ============Silicates (less than 1% crystalline silica): Mica...................................... 20 Soapstone................................. 20 Talc...................................... 20 Portland cement........................... 50 Graphite (natural).......................... 15 Coat dust (respirable fraction less than 5% ........... 2.4mg/M \3\ SiO2)...................................... ........... or For more than 5% SiO2....................... ........... 10mg/M \3\ ------------ ........... %SiO2=2 Inert or Nuisance Dust: Respirable fraction....................... 1 5mg/M \3\ Total dust................................ 505 15mg/M\3\------------------------------------------------------------------------Note: Conversion factors_mppcfx35.3=million particles per cubic meter =particles per c.c.\e\Millions of particles per cubic foot of air, based on impinger samples counted by light-field technics.\f\The percentage of crystalline silica in the formula is the amount determined from air-borne samples, except in those instances in which other methods have been shown to be applicable.\j\As determined by the membrane filter method at 430 x phase contrast magnification.\m\Both concentration and percent quartz for the application of this limit are to be determined from the fraction passing a size-selector with the following characteristics:
------------------------------------------------------------------------ Percent Aerodynamic diameter (unit density sphere) passing selector------------------------------------------------------------------------ 2 90 2.5 75 3.5 50 5.0 25 10 0------------------------------------------------------------------------The measurements under this note refer to the use of an AEC instrument. If the respirable fraction of coal dust is determined with a MRE the figure corresponding to that of 2.4 Mg/M \3\ in the table for coal dust is 4.5 Mg/M \3\
§ 50-204.65 Inspection of compressed gas cylinders.
§ 50-204.66 Acetylene.
§ 50-204.67 Oxygen.
§ 50-204.68 Hydrogen.
§ 50-204.69 Nitrous oxide.
§ 50-204.70 Compressed gases.
§ 50-204.71 Safety relief devices for compressed gas containers.
§ 50-204.72 Safe practices for welding and cutting on containers which have held combustibles.
