• Part Number: 1915 • Part Title: Occup. Safety and Health Standards for Shipyard Employment • Subpart: Z • Subpart Title: Toxic and Hazardous Substances • Standard Number: 1915.1000 • Title: Air contaminants

Wherever this section applies, an employee's exposure to any substance listed in Table Z-Shipyards of this section shall be limited in accordance with the requirements of the following paragraphs of this section.
1915.1000(a)(1)
"Substances with limits preceded by 'C'" - "Ceiling Values." An employee's exposure to any substance in Table Z-Shipyards, the exposure limit of which is preceded by a "C," shall at no time exceed the exposure limit given for that substance. If instantaneous monitoring is not feasible, then the ceiling shall be assessed as a 15-minute time weighted average exposure which shall not be exceeded at any time over a working day.
1915.1000(a)(2)
"Other Substances" - "8-hour Time Weighted Averages." An employee's exposure to any substance in Table Z-Shipyards, the exposure limit of which is not preceded by a "C," shall not exceed the 8-hour Time Weighted Average given for that substance in any 8-hour work shift of a 40-hour work week.
1915.1000(b)
[Reserved]
1915.1000(c)
[Reserved]
1915.1000(d)
"Computation formula." The computation formula which shall apply to employee exposure to more than one substance for which 8-hour time weighted averages are listed in subpart Z of 29 CFR part 1915 in order to determine whether an employee is exposed over the regulatory limit is as follows:
1915.1000(d)(1)
1915.1000(d)(1)(i)
The cumulative exposure for an 8-hour work shift shall be computed as follows:

E = (Ca Ta+CbTb+...Cn Tn) ÷ 8

Where:

E is the equivalent exposure for the working shift.
C is the concentration during any period of time T where the concentration remains constant.
T is the duration in hours of the exposure at the concentration C.

The value of E shall not exceed the 8-hour time weighted average specified in subpart Z of 29 CFR Part 1915 for the material involved.
1915.1000(d)(1)(ii)
To illustrate the formula prescribed in paragraph (d)(1)(i) of this section, assume that Substance A has an 8-hour time weighted average limit of 100 ppm noted in Table Z—Shipyards. Assume that an employee is subject to the following exposure:

Two hours exposure at 150 ppm
Two hours exposure at 75 ppm
Four hours exposure at 50 ppm

Substituting this information in the formula, we have (2 x 150 + 2 x 75 + 4 x 50) ÷ 8 = 81.25 ppm

Since 81.25 ppm is less than 100 ppm, the 8-hour time weighted average limit, the exposure is acceptable.
1915.1000(d)(2)
-
1915.1000(d)(2)(i)
in case of a mixture of air contaminants an employer shall compute the equivalent exposure as follows:

Em = (C1 ÷ L1+C2 ÷ L2)+...(Cn ÷ Ln)

Where:

E(m) is the equivalent exposure for the mixture.
C is the concentration of a particular contaminant.
L is the exposure limit for that substance specified in Subpart Z of 29 CFR Part 1915.
The value of E(m) shall not exceed unity (1).
1915.1000(d)(2)(ii)
To illustrate the formula prescribed in paragraph (d)(2)(i) of this section, consider the following exposures:
 Substance Actual concentration of 8 hour exposure (ppm) 18 hr. TWA PEL (ppm) B .......... 500 1000 C .......... 45 200 D .......... 40 200
Substituting in the formula, we have:
Em = 500 + 1,000 + 45 + 200 + 40 + 200
Em = 0.500 + 0.225 + 0.200
Em = 0.925

Since Em is less than unity (1), the exposure combination is within acceptable limits.

__________
NOTE: Because of the length of the table, explanatory Footnotes applicable to all substances are given below as well as at the end of the table. Footnotes specific only to a limited number of substances are also shown within the table.

1 [Reserved]
2 See Mineral Dusts Table.
3 Use Asbestos Limit 1915.1001.
4 See 1915.1001
* The PELs are 8-hour TWAs unless otherwise noted; a (C) designation denotes a ceiling limit. They are to be determined from breathing-zone air samples.
a Parts of vapor or gas per million parts of contaminated air by volume at 25 degrees C and 760 torr.
b Milligrams of substance per cubic meter of air. When entry is in this column only, the value is exact; when listed with a ppm entry, it is approximate.
c [Reserved]
d The CAS number is for information only. Enforcement is based on the substance name. For an entry covering more than one metal compound, measured as the metal, the CAS number for the metal is given - not CAS numbers for the individual compounds.
e [Reserved]
f [Reserved]
g For sectors excluded from 1915.1028 the limit is 10 ppm TWA.
h Where OSHA has published a proposal for a substance but has not issued a final rule, the proposal is referenced and the existing limit is published.
i [Reserved]
j Millions of particles per cubic foot of air, based on impinger samples counted by light-field techniques.
k The percentage of crystalline silica in the formula is the amount determined from airborne samples, except in those instances in which other methods have been shown to be applicable.
l [Reserved]
m Covers all organic and inorganic particulates not otherwise regulated. Same as Particulates Not Otherwise Regulated.
The 1970 TLV uses letter designations instead of a numerical value as follows:
A1 [Reserved]
A2 Polytetrafluoroethylene decomposition products. Because these products decompose in part by hydrolysis in alkaline solution, they can be quantitatively determined in air as fluoride to provide an index of exposure. No TLV is recommended pending determination of the toxicity of the products, but air concentrations should be minimal.
A3 Gasoline and/or Petroleum distillates. The composition of these materials varies greatly and thus a single TLV for all types of these materials is no longer applicable. The content of benzene, other aromatics and additives should be determined to arrive at the appropriate TLV.
E Simple asphyxiants. The limiting factor is the available oxygen which shall be at least 18 percent and be within the requirements addressing explosion in subpart B of part 1915.
```                       TABLE Z-SHIPYARDS
______________________________________________________________________
|            |        |              |
|            |        |              |  Skin
Substance        |CAS No. (d) |ppm (a*) | mg/m(3b*)(h)  | Desig-
|            |        |              | nation
_______________________|____________|________|______________|_________
|            |        |              |
Abate; see Temephos....|            |        |              |
Acetaldehyde...........|    75-07-0 |   200  |      360     | ....
Acetic acid............|    64-19-7 |    10  |       25     | ....
Acetic anhydride.......|   108-24-7 |     5  |       20     | ....
Acetone................|    67-64-1 |  1000  |     2400     | ....
Acetonitrile...........|    75-05-8 |    40  |       70     | ....
2-Acetylaminofluorene; |            |        |              |
see 1915.1014.........|    53-96-3 |        |              |
Acetylene..............|    74-86-2 |     E  |              |
Acetylene dichloride;  |            |        |              |
see                   |            |        |              |
1,2-Dichloroethylene..|            |        |              |
Acetylene tetrabromide.|    79-27-6 |   1    |       14     | ....
Acrolein...............|   107-02-8 |   0.1  |        0.25  | ....
Acrylamide.............|    79-06-1 | ...... |        0.3   |  X
Acrylonitrile;         |            |        |              |
see 1915.1045.........|   107-13-1 |        |              |
Aldrin.................|   309-00-2 | ...... |        0.25  |  X
Allyl alcohol..........|   107-18-6 |   2    |        5     |  X
Allyl chloride.........|   107-05-1 |   1    |        3     | ....
Allyl glycidyl ether...|            |        |              |
(AGE).................|   106-92-3 | (C)10  |    (C)45     | ....
Allyl propyl disulfide.|  2179-59-1 |   2    |       12     | ....
alpha-Alumina..........|  1344-28-1 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Aluminum (as Al) Metal.|  7429-90-5 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Alundum; see           |            |        |              |
alpha-Alumina.........|            |        |              |
4-Aminodiphenyl;       |            |        |              |
see 1915.1011.........|    92-67-1 |        |              |
2-Aminoethanol;        |            |        |              |
see Ethanolamine......|            |        |              |
2-Aminopyridine........|   504-29-0 |   0.5  |        2     | ....
Ammonia................|  7664-41-7 |  50    |       35     | ....
Ammonium sulfamate.....|  7773-06-0 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
n-Amyl acetate.........|   628-63-7 | 100    |      525     | ....
sec-Amyl acetate.......|   626-38-0 | 125    |      650     | ....
Aniline and homologs...|    62-53-3 |   5    |       19     |  X
Anisidine              |            |        |              |
(o-,p-isomers)........| 29191-52-4 | ...... |        0.5   |  X
Antimony and compounds |            |        |              |
(as Sb)...............|  7440-36-0 | ...... |        0.5   | ....
ANTU (alpha            |            |        |              |
Naphthylthiourea).....|    86-88-4 | ...... |        0.3   | ....
Argon..................|  7440-37-1 |   E    |              |
Arsenic, inorganic     |            |        |              |
compounds (as As);    |            |        |              |
see 1915.1018.........|  7440-38-2 | ...... |     .......  | ....
Arsenic, organic       |            |        |              |
compounds (as As).....|  7440-38-2 | ...... |        0.5   | ....
Arsine.................|  7784-42-1 |   0.05 |        0.2   | ....
Asbestos;              |            |        |              |
see 1915.1001.........|            |        |              |
Azinphos-methyl........|    86-50-0 | ...... |        0.2   |  X
Barium, soluble        |            |        |              |
compounds (as Ba).....|  7440-39-3 | ...... |        0.5   | ....
Barium sulfate.........|  7727-43-7 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Benomyl................| 17804-35-2 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Benzene(g); See        |            |        |              |
1915.1028.............|    71-43-2 |        |              |
Benzidine;             |            |        |              |
See 1915.1010.........|    92-87-5 |        |              |
p-Benzoquinone;        |            |        |              |
see Quinone.          |            |        |              |
Benzo(a)pyrene; see    |            |        |              |
Coal tar pitch        |            |        |              |
volatiles.............|            |        |              |
Benzoyl peroxide.......|    94-36-0 | ...... |        5     | ....
Benzyl chloride........|   100-44-7 |   1    |        5     | ....
Beryllium and          |            |        |              |
beryllium compounds   |            |        |              |
(as Be)...............|  7440-41-7 | ...... |        0.002 | ....
Biphenyl; see Diphenyl.|            |        |              |
Bismuth telluride,     |            |        |              |
Undoped...............|  1304-82-1 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Bisphenol A; see       |            |        |              |
Diglycidyl ether.     |            |        |              |
Boron oxide............|  1303-86-2 |        |              |
Total dust............|            | ...... |       15     | ....
Boron tribromide.......| 10294-33-4 |   1    |       10     | ....
Boron trifluoride......|  7637-07-2 | (C)1   |     (C)3     | ....
Bromine................|  7726-95-6 |   0.1  |        0.7   | ....
Bromine pentafluoride..|  7789-30-2 |   0.1  |        0.7   | ....
Bromoform..............|    75-25-2 |   0.5  |        5     |  X
(1,3-Butadiene); See  |            |        |              |
29 CFR 1910.1051;     |   106-99-0 | 1 ppm/5|              | ....
29 CFR 1910.19(l).....|            |ppm STEL|              |
Butanethiol;           |            |        |              |
see Butyl mercaptan.  |            |        |              |
2-Butanone             |            |        |              |
(Methyl ethyl ketone) |    78-93-3 | 200    |      590     | ....
2-Butoxyethanol........|   111-76-2 |  50    |      240     |  X
n-Butyl-acetate........|   123-86-4 | 150    |      710     | ....
sec-Butyl acetate......|   105-46-4 | 200    |      950     | ....
tert-Butyl-acetate.....|   540-88-5 | 200    |      950     | ....
n-Butyl alcohol........|    71-36-3 | 100    |      300     | ....
sec-Butyl alcohol......|    78-92-2 | 150    |      450     | ....
tert-Butyl alcohol.....|    75-65-0 | 100    |      300     | ....
Butylamine.............|   109-73-9 |(C)5    |    (C)15     |  X
tert-Butyl chromate    |            |        |              |
(as CrO3).............|  1189-85-1 |        |              |
see 1915.1026n       |            |        |              |
n-Butyl glycidyl ether |            |        |              |
(BGE).................|  2426-08-6 |  50    |      270     | ....
Butyl mercaptan........|   109-79-5 |   0.5  |        1.5   | ....
p-tert-Butyltoluene....|    98-51-1 |  10    |       60     | ....
Cadmium dust fume      |            |        |              |
(as Cd);              |            |        |              |
see 1915.1027.........|  7440-43-9 | ...... |    .......   | ....
Calcium Carbonate......|  1317-65-3 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Calcium hydroxide......|  1305-62-0 | ...... |    .......   | ....
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Calcium oxide..........|  1305-78-8 | ...... |        5     | ....
Calcium silicate.......|  1344-95-2 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Calcium sulfate........|  7778-18-9 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Camphor, synthetic.....|    76-22-2 | ...... |        2     | ....
Carbaryl (Sevin).......|    63-25-2 | ...... |        5     | ....
Carbon black...........|  1333-86-4 | ...... |        3.5   | ....
Carbon dioxide.........|   124-38-9 |  5000  |     9000     | ....
Carbon disulfide.......|    75-15-0 |    20  |       60     |  X
Carbon monoxide........|   630-08-0 |    50  |       55     | ....
Carbon tetrachloride...|    56-23-5 |    10  |       65     |  X
Cellulose..............|  9004-34-6 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Chlordane..............|    57-74-9 | ...... |        0.5   |  X
Chlorinated camphene...|  8001-35-2 | ...... |        0.5   |  X
Chlorinated diphenyl   |            |        |              |
oxide.................| 55720-99-5 | ...... |        0.5   | ....
Chlorine...............|  7782-50-5 |     1  |        3     | ....
Chlorine trifluoride...|  7790-91-2 | (C)0.1 |     (C)0.4   | ....
Chloroacetaldehyde.....|   107-20-0 |  (C)1  |     (C)3     | ....
a-Chloroacetophenone   |            |        |              |
(Phenacyl chloride)...|   532-27-4 |   0.05 |        0.3   | ....
Chlorobenzene..........|   108-90-7 |  75    |      350     | ....
o-Chlorobenzylidene    |            |        |              |
malononitrile.........|  2698-41-1 |   0.05 |        0.4   | ....
Chlorobromomethane.....|    74-97-5 | 200    |     1050     | ....
See beta-Chloroprene..|            |        |              |
Chlorodiphenyl         |            |        |              |
(42% Chlorine)(PCB)...| 53469-21-9 |....... |        1     |  X
Chlorodiphenyl         |            |        |              |
(54% Chlorine)(PCB)...| 11097-69-1 |....... |        0.5   |  X
1-Chloro-2,            |            |        |              |
3-epoxypropane;       |            |        |              |
See Epichlorohydrin.  |            |        |              |
2-Chloroethanol;  See  |            |        |              |
Ethylene chlorohydrin |            |        |              |
Chloroethylene;        |            |        |              |
See Vinyl chloride.   |            |        |              |
Chloroform             |            |        |              |
(Trichloromethane)....|    67-66-3 |  50    |      240     | ....
bis(Chloromethyl)      |            |        |              |
ether; see 1915.1008..|   542-88-1 |        |              |
Chloromethyl methyl    |            |        |              |
ether; see 1915.1006..|   107-30-2 |        |              |
1-Chloro-1-nitropropane|   600-25-9 |  20    |      100     | ....
Chloropicrin...........|    76-06-2 |   0.1  |        0.7   | ....
beta-Chloroprene.......|   126-99-8 |  25    |       90     |  X
2-Chloro-6             |            |        |              |
(trichloromethyl)     |            |        |              |
pyridine..............|  1929-82-4 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Chromic acid and       |            |        |              |
chromates (as CrO3)   | Varies with| ...... |        0.1   | ....
|  compound  |        |              |
Chromium (II) compounds|            |        |              |
(as Cr)...............|  7440-47-3 | ...... |        0.5   | ....
Chromium (III)         |            |        |              |
compounds (as Cr).....|  7440-47-3 | ...... |        0.5   | ....
Chromium (VI) compounds|            |        |              |
see 1915.1026o        |            |        |              |
Chromium metal and     |            |        |              |
insol. salts (as Cr)..|  7440-47-3 | ...... |        1     | ....
Chrysene; see Coal tar |            |        |              |
pitch volatiles.......|            |        |              |
Clopidol...............|  2971-90-6 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Coal tar pitch         |            |        |              |
volatiles (benzene    |            |        |              |
soluble fraction),    |            |        |              |
anthracene, BaP,      |            |        |              |
phenanthrene,         |            |        |              |
acridine, chrysene,   |            |        |              |
pyrene................| 65966-93-2 | ...... |        0.2   | ....
Cobalt metal, dust,    |            |        |              |
and fume (as Co)......|  7440-48-4 | ...... |        0.1   | ....
Copper.................|  7440-50-8 |        |              |
Fume (as Cu)..........|            | ...... |        0.1   | ....
Dusts and mists       |            |        |              |
(as Cu)...............|            | ...... |        1     | ....
Corundum; see Emery.   |            |        |              |
Cotton dust (raw)......|            | ...... |        1     |
Crag herbicide (Sesone)|   136-78-7 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Cresol, all isomers....|  1319-77-3 |   5    |       22     |  X
Crotonaldehyde.........|   123-73-9 |   2    |        6     |
|  4170-30-3 |        |              |
Cumene.................|    98-82-8 |  50    |      245     |  X
Cyanides (as CN).......| Varies with| ...... |        5     | ....
|  Compound  |        |              |
Cyanogen...............|   460-19-5 |  10    |    .......   | ....
Cyclohexane............|   110-82-7 | 300    |     1050     | ....
Cyclohexanol...........|   108-93-0 |  50    |      200     | ....
Cyclohexanone..........|   108-94-1 |  50    |      200     | ....
Cyclohexene............|   110-83-8 | 300    |     1015     | ....
Cyclonite .............|   121-82-4 | ...... |        1.5   |  X
Cyclopentadiene........|   542-92-7 |  75    |      200     | ....
2,4-D (Dichlorophen-   |            |        |              |
oxyacetic acid).......|    94-75-7 | ...... |       10     | ....
Decaborane.............| 17702-41-9 |   0.05 |        0.3   |  X
Demeton (Systox).......|  8065-48-3 | ...... |        0.1   |  X
Diacetone alcohol      |            |        |              |
(4-Hydroxy-4-methyl-  |            |        |              |
2-pentanone)..........|   123-42-2 |  50    |      240     | ....
1,2-Diaminoethane;     |            |        |              |
see Ethylenediamine...|            |        |              |
Diazomethane...........|   334-88-3 |   0.2  |        0.4   | ....
Diborane...............| 19287-45-7 |   0.1  |        0.1   | ....
1,2-Dibromo-3-         |            |        |              |
chloropropane (CBCP); |            |        |              |
see 1915.1044.........|    96-12-8 |        |     .......  |
1,2-Dibromoethane; see |            |        |              |
Ethylene dibromide....|            |        |              |
Dibutyl phosphate......|   107-66-4 |   1    |        5     | ....
Dibutyl phthalate......|    84-74-2 | ...... |        5     | ....
Dichloroacetylene......|  7572-29-4 | (C)0.1 |    (C)0.4    | ....
o-Dichlorobenzene......|    95-50-1 | (C)50  |   (C)300     | ....
p-Dichlorobenzene......|   106-46-7 |    75  |      450     | ....
3,3'-Dichlorobenzidine;|            |        |              |
see 1915.1007.........|    91-94-1 |        |              |
Dichlorodifluoromethane|    75-71-8 | 1000   |     4950     | ....
1,3-Dichloro-5,        |            |        |              |
5-dimethyl hydantoin..|   118-52-5 | ...... |        0.2   | ....
Dichlorodiphenyltri-   |            |        |              |
chloroethane (DDT)....|    50-29-3 | ...... |        1     |  X
1,1-Dichloroethane.....|    75-34-3 | 100    |      400     | ....
1,2-Dichloroethane; see|            |        |              |
Ethylene dichloride...|            |        |              |
1,2-Dichloroethylene...|   540-59-0 | 200    |      790     | ....
Dichloroethyl ether....|   111-44-4 | (C)15  |    (C)90     |  X
Dichloromethane; see   |            |        |              |
Methylene chloride....|            |        |              |
Dichloromonofluoro-    |            |        |              |
methane...............|    75-43-4 | 1000   |     4200     | ....
1,1-Dichloro-1-        |            |        |              |
nitroethane...........|   594-72-9 | (C)10  |    (C)60     | ....
1,2-Dichloropropane;   |            |        |              |
see                   |            |        |              |
Propylene dichloride..|            |        |              |
Dichlorotetrafluoro-   |            |        |              |
ethane................|    76-14-2 | 1000   |     7000     | ....
Dichlorvos (DDVP)......|    62-73-7 | ...... |        1     |  X
Dicyclopentadienyl iron|   102-54-5 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Dieldrin...............|    60-57-1 | ...... |        0.25  |  X
Diethylamine...........|   109-89-7 |  25    |       75     | ....
2-Diethylaminoethanol..|   100-37-8 |  10    |       50     | ....
Diethylene triamine....|   111-40-0 | (C)10  |    (C)42     |  X
Diethyl ether;         |            |        |              |
see Ethyl ether.......|            |        |              |
Difluorodibromomethane.|    75-61-6 | 100    |      860     | ....
Diglycidyl ether (DGE).|  2238-07-5 | (C)0.5 |     (C)2.8   | ....
Dihydroxybenzene;      |            |        |              |
see Hydroquinone......|            |        |              |
Diisobutyl ketone......|   108-83-8 |  50    |      290     | ....
Diisopropylamine.......|   108-18-9 |   5    |       20     |  X
4-Dimethylaminoazo-    |            |        |              |
benzene;              |            |        |              |
see 1915.1015.........|    60-11-7 |        |              |
Dimethoxymethane;      |            |        |              |
see Methylal..........|            |        |              |
Dimethyl acetamide.....|   127-19-5 |  10    |       35     |  X
Dimethylamine..........|   124-40-3 |  10    |       18     | ....
Dimethylaminobenzene;  |            |        |              |
see Xylidine..........|            |        |              |
Dimethylaniline        |            |        |              |
(N,N-Dimethylaniline) |   121-69-7 |   5    |       25     |  X
Dimethylbenzene;       |            |        |              |
see Xylene............|            |        |              |
Dimethyl-1,2-dibromo-2,|            |        |              |
2-dichloroethyl       |            |        |              |
phosphate.............|   300-76-5 | ...... |        3     | ....
Dimethylformamide......|    68-12-2 |  10    |       30     |  X
2,6-Dimethyl-4-        |            |        |              |
heptanone; see        |            |        |              |
Diisobutyl ketone.....|            |        |              |
1,1-Dimethylhydrazine..|    57-14-7 |   0.5  |        1     |  X
Dimethylphthalate......|   131-11-3 | ...... |        5     | ....
Dimethyl sulfate.......|    77-78-3 |   1    |        5     |  X
Dinitrobenzene         |            |        |              |
(all isomers).........|            |        |        1     |  X
(ortho)...............|   528-29-0 |        |              |
(meta)................|    99-65-0 |        |              |
(para)................|   100-25-4 |        |              |
Dinitro-o-cresol.......|   534-52-1 | ...... |        0.2   |  X
Dinitrotoluene.........| 25321-14-6 | ...... |        1.5   |  X
Dioxane                |            |        |              |
(Diethylene dioxide)..|   123-91-1 | 100    |      360     |  X
Diphenyl (Biphenyl)....|    92-52-4 |   0.2  |        1     | ....
Diphenylamine .........|   122-39-4 | ...... |       10     | ....
Diphenylmethane        |            |        |              |
diisocyanate; see     |            |        |              |
Methylene bisphenyl   |            |        |              |
isocyanate............|            |        |              |
Dipropylene glycol     |            |        |              |
methyl ether..........| 34590-94-8 | 100    |      600     |  X
Di-sec octyl phthalate |            |        |              |
(Di-(2-ethylhexyl)    |            |        |              |
phthalate)............|   117-81-7 | ...... |        5     | ....
Emery..................| 12415-34-8 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Endosulfan.............|   115-29-7 | ...... |        0.1   |  X
Endrin.................|    72-20-8 | ...... |        0.1   |  X
Epichlorohydrin........|   106-89-8 |   5    |       19     |  X
EPN....................|  2104-64-5 | ...... |        0.5   |  X
1,2-Epoxypropane; see  |            |        |              |
Propylene oxide.......|            |        |              |
2,3-Epoxy-1-propanol;  |            |        |              |
see Glycidol..........|            |        |              |
Ethane.................|    74-84-0 |   E    |              |
Ethanethiol;  see      |            |        |              |
Ethyl mercaptan.......|            |        |              |
Ethanolamine...........|   141-43-5 |   3    |        6     | ....
2-Ethoxyethanol        |            |        |              |
(Cellosolve)..........|   110-80-5 | 200    |      740     |  X
2-Ethoxyethyl acetate  |            |        |              |
(Cellosolve acetate)..|   111-15-9 | 100    |      540     |  X
Ethyl acetate..........|   141-78-6 | 400    |     1400     | ....
Ethyl acrylate.........|   140-88-5 |  25    |      100     |  X
Ethyl alcohol (Ethanol)|    64-17-5 | 1000   |     1900     | ....
Ethylamine.............|    75-04-7 |  10    |       18     | ....
Ethyl amyl ketone      |            |        |              |
(5-Methyl-3-          |            |        |              |
heptanone)............|   541-85-5 |  25    |      130     | ....
Ethyl benzene..........|   100-41-4 | 100    |      435     | ....
Ethyl bromide..........|    74-96-4 | 200    |      890     | ....
Ethyl butyl ketone     |            |        |              |
(3-Heptanone).........|   106-35-4 |  50    |      230     | ....
Ethyl chloride.........|    75-00-3 | 1000   |     2600     | ....
Ethyl ether............|    60-29-7 | 400    |     1200     | ....
Ethyl formate..........|   109-94-4 | 100    |      300     | ....
Ethyl mercaptan........|    75-08-1 |   0.5  |        1     | ....
Ethyl silicate.........|    78-10-4 | 100    |      850     | ....
Ethylene...............|    74-85-1 |   E    |              |
Ethylene chlorohydrin..|   107-07-3 |   5    |       16     |  X
Ethylenediamine........|   107-15-3 |  10    |       25     | ....
Ethylene dibromide.....|   106-93-4 |(C)25   |   (C)190     |  X
Ethylene dichloride    |            |        |              |
(1,2-Dichloroethane)..|   107-06-2 |  50    |      200     | ....
Ethylene glycol        |            |        |              |
dinitrate.............|   628-96-6 | (C)0.2 |     (C)1     |  X
Ethylene glycol methyl |            |        |              |
acetate; see Methyl   |            |        |              |
cellosolve acetate....|            |        |              |
Ethyleneimine;         |            |        |              |
see 1915.1012.........|   151-56-4 |        |              |
Ethylene oxide;        |            |        |              |
see 1915.1047.........|    75-21-8 |        |              |
Ethylidene chloride;   |            |        |              |
see 1,1-Dichlorethane |            |        |              |
N-Ethylmorpholine......|   100-74-3 |  20    |       94     |  X
Ferbam.................| 14484-64-1 |        |              |
Total dust............|            | ...... |       15     | ....
Ferrovanadium dust.....| 12604-58-9 | ...... |        1     | ....
Fibrous Glass..........|            |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction   |            | ...... |        5     | ....
Fluorides (as F).......| Varies with| ...... |        2.5   | ....
|  compound  |        |              |
Fluorine...............|  7782-41-4 |   0.1  |        0.2   | ....
Fluorotrichloromethane |            |        |              |
(Trichloro-           |            |        |              |
fluoromethane)........|    75-69-4 | 1000   |     5600     | ....
Formaldehyde;          |            |        |              |
see 1915.1048.........|    50-00-0 |        |              |
Formic acid............|    64-18-6 |   5    |        9     | ....
Furfural...............|    98-01-1 |   5    |       20     |  X
Furfuryl alcohol.......|    98-00-0 |  50    |      200     | ....
Gasoline...............|  8006-61-9 |        |       A3     | ....
Glycerin (mist)........|    56-81-5 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Glycidol...............|   556-52-5 |  50    |      150     | ....
Glycol monoethyl ether;|            |        |              |
see 2-Ethoxyethanol...|            |        |              |
Graphite, natural      |            |        |              |
respirable dust.......|  7782-42-5 |   2    |       2      |   2
Graphite, synthetic....|            |        |              |
Total dust............|            | ...... |       15     | ....
Respirable Fraction...|            | ...... |        5     | ....
Guthion;               |            |        |              |
see Azinphos methyl...|            |        |              |
Gypsum.................| 13397-24-5 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Hafnium................|  7440-58-6 | ...... |        0.5   | ....
Helium.................|  7440-59-7 |   E    |              |
Heptachlor.............|    76-44-8 | ...... |        0.5   |  X
Heptane (n-Heptane)....|   142-82-5 | 500    |     2000     | ....
Hexachloroethane.......|    67-72-1 |   1    |       10     |  X
Hexachloronaphthalene..|  1335-87-1 | ...... |        0.2   |  X
n-Hexane...............|   110-54-3 | 500    |     1800     | ....
2-Hexanone (Methyl     |            |        |              |
n-butyl ketone).......|   591-78-6 | 100    |      410     | ....
Hexone (Methyl         |            |        |              |
isobutyl ketone)......|   108-10-1 | 100    |      410     | ....
sec-Hexyl acetate......|   108-84-9 |  50    |      300     | ....
Hydrazine..............|   302-01-2 |   1    |        1.3   |  X
Hydrogen...............|  1333-74-0 |   E    |              |
Hydrogen bromide.......| 10035-10-6 |   3    |       10     | ....
Hydrogen chloride......|  7647-01-0 | (C)5   |     (C)7     | ....
Hydrogen cyanide.......|    74-90-8 |  10    |       11     |  X
Hydrogen fluoride      |            |        |              |
(as F)................|  7664-39-3 |   3    |        2     | ....
Hydrogen peroxide......|  7722-84-1 |   1    |        1.4   | ....
Hydrogen selenide      |            |        |              |
(as Se)...............|  7783-07-5 |   0.05 |              |
Hydrogen sulfide.......|  7783-06-4 |  10    |       15     | ....
Hydroquinone...........|   123-31-9 | ...... |        2     | ....
Indene.................|    95-13-6 |  10    |       45     | ....
Indium and compounds   |            |        |              |
(as in)...............|  7440-74-6 | ...... |        0.1   | ....
Iodine.................|  7553-56-2 | (C)0.1 |     (C)1     | ....
Iron oxide fume........|  1309-37-1 | ...... |       10     | ....
Iron salts (soluble)   |            |        |              |
(as Fe)...............| Varies with| ...... |        1     | ....
|  compound  |        |              |
Isomyl acetate.........|   123-92-2 | 100    |      525     | ....
Isomyl alcohol         |            |        |              |
(primary and          |            |        |              |
secondary)............|   123-51-3 | 100    |      360     | ....
Isobutyl acetate.......|   110-19-0 | 150    |      700     | ....
Isobutyl alcohol.......|    78-83-1 | 100    |      300     | ....
Isophorone.............|    78-59-1 |  25    |      140     | ....
Isopropyl acetate......|   108-21-4 | 250    |      950     | ....
Isopropyl alcohol......|    67-63-0 | 400    |      980     | ....
Isopropylamine.........|    75-31-0 |   5    |       12     | ....
Isopropyl ether........|   108-20-3 | 500    |     2100     | ....
Isopropyl glycidyl     |            |        |              |
ether (IGE)...........|  4016-14-2 |  50    |      240     | ....
Kaolin.................|  1332-58-7 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Ketene.................|   463-51-4 |   0.5  |        0.9   | ....
Lead inorganic (as Pb);|            |        |              |
see 1915.1025.........|  7439-92-1 | ...... |   .........  | ....
Limestone..............|  1317-65-3 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Lindane................|    58-89-9 | ...... |        0.5   |  X
Lithium hydride........|  7580-67-8 | ...... |        0.025 | ....
L.P.G. (Liquified      |            |        |              |
petroleum gas)........| 68476-85-7 | 1000   |     1800     |
Magnesite..............|   546-93-0 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Magnesium oxide fume...|  1309-48-4 |        |              |
Total Particulate.....|            |  15    |    ........  | ....
Malathion..............|   121-75-5 |        |              |
Total dust............|            | ...... |       15     |  X
Maleic anhydride.......|   108-31-6 |   0.25 |              |
Manganese compounds    |            |        |              |
(as Mn)...............|  7439-96-5 | ...... |     (C)5     | ....
Manganese fume (as Mn).|  7439-96-5 | ...... |     (C)5     | ....
Marble.................|  1317-65-3 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Mercury (aryl and      |            |        |              |
inorganic)(as Hg).....|  7439-97-6 |        |        0.1   |  X
Mercury (organo) alkyl |            |        |              |
compounds (as Hg).....|  7439-97-6 |        |        0.01  |  X
Mercury (vapor) (as Hg)|  7439-97-6 |        |        0.1   |  X
Mesityl oxide..........|   141-79-7 |  25    |      100     | ....
Methane................|    74-82-8 |   E    |              |
Methanethiol;          |            |        |              |
see Methyl mercaptan..|            |        |              |
Methoxychlor...........|    72-43-5 |        |              |
Total dust............|            | ...... |       15     | ....
2-Methoxyethanol;      |            |        |              |
(Methyl cellosolve)...|   109-86-4 |  25    |       80     |  X
2-Methoxyethyl acetate |            |        |              |
(Methyl cellosolve    |            |        |              |
acetate)..............|   110-49-6 |  25    |      120     |  X
Methyl acetate.........|    79-20-9 | 200    |      610     | ....
Methyl acetylene       |            |        |              |
(Propyne).............|    74-99-7 | 1000   |     1650     | ....
Methyl acetylene       |            |        |              |
propadiene mixture    |            |        |              |
(MAPP)................|            | 1000   |     1800     | ....
Methyl acrylate........|    96-33-3 |  10    |       35     |  X
Methylal               |            |        |              |
(Dimethoxy-methane)...|   109-87-5 | 1000   |     3100     | ....
Methyl alcohol.........|    67-56-1 |  200   |      260     | ....
Methylamine............|    74-89-5 |  10    |       12     | ....
Methyl amyl alcohol;   |            |        |              |
see Methyl Isobutyl   |            |        |              |
carbinol..............|            |        |              |
Methyl n-amyl ketone...|   110-43-0 | 100    |      465     | ....
Methyl bromide.........|    74-83-9 | (C)20  |    (C)80     |  X
Methyl butyl ketone;   |            |        |              |
see 2-Hexanone........|            |        |              |
Methyl cellosolve;     |            |        |              |
see 2-Methoxyethanol..|            |        |              |
Methyl cellosolve      |            |        |              |
acetate;              |            |        |              |
see 2-Methoxyethyl    |            |        |              |
acetate...............|            |        |              |
Methyl chloride........|    74-87-3 |   100  |      210     | ....
Methyl chloroform      |            |        |              |
(1,1,1-Trichloro-     |            |        |              |
ethane)...............|    71-55-6 |   350  |     1900     | ....
Methylcyclohexane......|   108-87-2 |   500  |     2000     | ....
Methylcyclohexanol.....| 25639-42-3 |   100  |      470     | ....
o-Methylcyclohexanone..|   583-60-8 |   100  |      460     |  X
Methylene chloride:    |            |        |              |
see 1910.1052.........|            |        |              |
Methyl ethyl ketone    |            |        |              |
(MEK); see 2-Butanone |            |        |              |
Methyl formate.........|   107-31-3 |   100  |      250     | ....
Methyl hydrazine       |            |        |              |
(Monomethyl           |            |        |              |
hydrazine)............|    60-34-4 |(C)0.2  |     (C)0.35  |  X
Methyl iodide..........|    74-88-4 |   5    |       28     |  X
Methyl isoamyl ketone..|   110-12-3 |  100   |      475     | ....
Methyl isobutyl        |            |        |              |
carbinol..............|   108-11-2 |   25   |      100     |  X
Methyl isobutyl ketone;|            |        |              |
see Hexone............|            |        |              |
Methyl isocyanate......|   624-83-9 |   0.02 |        0.05  |  X
Methyl mercaptan.......|    74-93-1 |   0.5  |        1     | ....
Methyl methacrylate....|    80-62-6 |  100   |      410     | 100
Methyl propyl ketone;  |            |        |              |
see 2-Pentanone.......|            |        |              |
Methyl silicate........|   681-84-5 |   5    |       30     | ....
alpha-Methyl styrene...|    98-83-9 |(C)100  |   (C)480     | ....
Methylene bisphenyl    |            |        |              |
isocyanate (MDI)......|   101-68-8 |(C)0.02 |     (C)0.2   | ....
Mica; see Silicates....|            |        |              |
Mineral wool...........|            |        |              |
Total dust............|            | ...... |       15     | ....
Respirable dust.......|            | ...... |        5     | ....
Molybdenum (as Mo).....|  7439-98-7 |        |              |
Soluble compounds.....|            | ...... |        5     | ....
Insoluble Compounds   |            |        |              |
Total dust..........|            | ...... |       15     | ....
Monomethyl aniline.....|   100-61-8 |   2    |        9     |  X
Monomethyl hydrazine;  |            |        |              |
see Methyl hydrazine..|            |        |              |
Morpholine.............|   110-91-8 |  20    |       70     |  X
Naphtha (Coal tar).....|  8030-30-6 | 100    |      400     | ....
Naphthalene............|    91-20-3 |  10    |       50     | ....
alpha-Naphthylamine;   |            |        |              |
see 1915.1004.........|   134-32-7 |        |              |
beta-Naphthylamine;    |            |        |              |
see 1915.1009.........|    91-59-8 |        |              | ....
Neon...................|  7440-01-9 |   E    |              |
Nickel carbonyl (as Ni)| 13463-39-3 |   0.001|        0.007 | ....
Nickel, metal and      |            |        |              |
insoluble compounds   |            |        |              |
(as Ni)...............|  7440-02-0 | ...... |        1     | ....
Nickel, soluble        |            |        |              |
compounds (as Ni).....|  7440-02-0 | ...... |        1     | ....
Nicotine...............|    54-11-5 | ...... |        0.5   |  X
Nitric acid............|  7697-37-2 |   2    |        5     | ....
Nitric oxide...........| 10102-43-9 |  25    |       30     | ....
p-Nitroaniline.........|   100-01-6 |   1    |        6     |  X
Nitrobenzene...........|    98-95-3 |   1    |        5     |  X
p-Nitrochlorobenzene...|   100-00-5 | ...... |        1     |  X
4-Nitrodiphenyl;       |            |        |              |
see 1915.1003.........|    92-93-3 |        |              |
Nitroethane............|    79-24-3 |  100   |      310     | ....
Nitrogen...............|  7727-37-9 |   E    |              |
Nitrogen dioxide.......| 10102-44-0 | (C)5   |     (C)9     | ....
Nitrogen trifluoride...|  7783-54-2 |  10    |       29     | ....
Nitroglycerin..........|    55-63-0 |(C)0.2  |     (C)2     |  X
Nitromethane...........|    75-52-5 | 100    |      250     | ....
1-Nitropropane.........|   108-03-2 |  25    |       90     | ....
2-Nitropropane.........|    79-46-9 |  25    |       90     | ....
N-Nitrosodimethylamine;|            |        |              |
see 1915.1016         |    62-79-9 |        |              | ....
Nitrotoluene           |            |        |              |
(all isomers).........|            |   5    |       30     |  X
o-isomer..............|    88-72-2 |        |              |
m-isomer..............|    99-08-1 |        |              |
p-isomer..............|    99-99-0 |        |              |
Nitrotrichloromethane; |            |        |              |
see Chloropicrin......|            |        |              |
Nitrous oxide..........| 10024-97-2 |   E    |              |
Octachloronaphthalene..|  2234-13-1 | ...... |        0.1   |  X
Octane.................|   111-65-9 |  400   |     1900     | ....
Oil mist, mineral......|  8012-95-1 | ...... |        5     | ....
Osmium tetroxide       |            |        |              |
(as Os)...............| 20816-12-0 | ...... |        0.002 | ....
Oxalic acid............|   144-62-7 | ...... |        1     | ....
Oxygen difluoride......|  7783-41-7 |   0.05 |        0.1   | ....
Ozone..................| 10028-15-6 |   0.1  |        0.2   | ....
Paraquat, respirable   |            |        |              |
dust..................|  4685-14-7 | ...... |        0.5   |  X
|  1910-42-5 |        |              |
|  2074-50-2 |        |              |
Parathion..............|    56-38-2 | ...... |        0.1   | ....
Particulates not       |            |        |              |
otherwise regulated...|            |        |              |
Total dust organic    |            |        |              |
and inorganic.........|            | ...... |       15     | ....
PCB; see Chlorodiphenyl|            |        |              |
(42% and 54%          |            |        |              |
chlorine).............|            |        |              |
Pentaborane............| 19624-22-7 |   0.005|        0.01  | ....
Pentachloronaphthalene.|  1321-64-8 | ...... |        0.5   |  X
Pentachlorophenol......|    87-86-5 | ...... |        0.5   |  X
Pentaerythritol........|   115-77-5 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Pentane................|   109-66-0 |  500   |     1500     | ....
2-Pentanone (Methyl    |            |        |              |
propyl ketone)........|   107-87-9 |  200   |      700     | ....
Perchloroethylene      |            |        |              |
(Tetrachloroethylene) |   127-18-4 |  100   |      670     | ....
Perchloromethyl        |            |        |              |
mercaptan.............|   594-42-3 |   0.1  |        0.8   | ....
Perchloryl fluoride....|  7616-94-6 |   3    |       13.5   | ....
Perlite................| 93763-70-3 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Petroleum distillates  |            |        |              |
(Naphtha)(Rubber      |            |        |              |
Solvent)..............|            |        |      A3      | ....
Phenol.................|   108-95-2 |   5    |       19     |  X
p-Phenylene diamine....|   106-50-3 | ...... |        0.1   |  X
Phenyl ether, vapor....|   101-84-8 |   1    |        7     | ....
Phenyl ether-biphenyl  |            |        |              |
mixture, vapor........|            |   1    |        7     | ....
Phenylethylene;        |            |        |              |
see Styrene...........|            |        |              |
Phenyl glycidyl ether  |            |        |              |
(PGE).................|   122-60-1 |  10    |       60     | ....
Phenylhydrazine........|   100-63-0 |   5    |       22     |  X
Phosdrin (Mevinphos)...|  7786-34-7 | ...... |        0.1   |  X
Phosgene (Carbonyl     |            |        |              |
chloride).............|    75-44-5 |   0.1  |        0.4   | ....
Phosphine..............|  7803-51-2 |   0.3  |        0.4   | ....
Phosphoric acid........|  7664-38-2 | ...... |        1     | ....
Phosphorus (yellow)....|  7723-14-0 | ...... |        0.1   | ....
Phosphorus             |            |        |              |
pentachloride.........| 10026-13-8 | ...... |        1     | ....
Phosphorus pentasulfide|  1314-80-3 | ...... |        1     | ....
Phosphorus trichloride.|  7719-12-2 |   0.5  |        3     | ....
Phthalic anhydride.....|    85-44-9 |   2    |       12     | ....
Picloram...............|  1918-02-1 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Picric acid............|    88-89-1 | ...... |        0.1   | ....
Piperazine             |            |        |              |
dihydrochloride.......|   142-64-3 | ...... |    .......   |  X
Pindone (2-Pivalyl-1,  |            |        |              |
3-indandione).........|    83-26-1 | ...... |        0.1   | ....
Plaster of paris.......| 26499-65-0 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Platinum (as Pt).......|  7440-06-4 |        |              |
Metal.................|            | ...... | ............ | ....
Soluble Salts.........|            | ...... |        0.002 | ....
Polytetrafluoroethylene|            |        |              |
decomposition         |            |        |              |
products..............|            |        |       A2     |
Portland cement........| 65997-15-1 |        |              |
Total dust............|            |  15    |    .......   |  10
Respirable fraction...|            |   5    |    .......   | ....
Propargyl alcohol......|   107-19-7 |   1    |    .......   |  X
beta-Propriolactone;   |            |        |              |
see 1915.1013.........|    57-57-8 |        |              |
Propionic acid.........|    79-09-4 | ...... |    .......   | ....
n-Propyl acetate.......|   109-60-4 |  200   |      840     | ....
n-Propyl alcohol.......|    71-23-8 |  200   |      500     | ....
n-Propyl nitrate.......|   627-13-4 |   25   |      110     | ....
Propylene dichloride...|    78-87-5 |   75   |      350     | ....
Propylene imine........|    75-55-8 |    2   |        5     |  X
Propylene oxide........|    75-56-9 |  100   |      240     | ....
Propyne; see Methyl    |            |        |              |
acetylene.............|            |        |              |
Pyrethrum..............|  8003-34-7 | ...... |        5     | ....
Pyridine...............|   110-86-1 |   5    |       15     | ....
Quinone................|   106-51-4 |   0.1  |        0.4   | ....
RDX: see Cyclonite.....|            |        |              |
Rhodium (as Rh), metal |            |        |              |
fume and insoluble    |            |        |              |
compounds.............|  7440-16-6 | ...... |        0.1   | ....
Rhodium (as Rh),       |            |        |              |
soluble compounds.....|  7440-16-6 | ...... |        0.001 | ....
Ronnel.................|   299-84-3 | ...... |       10     | ....
Rotenone...............|    83-79-4 | ...... |        5     | ....
Rouge..................|            | ...... |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Selenium compounds     |            |        |              |
(as Se)...............|  7782-49-2 | ...... |        0.2   | ....
Selenium hexafluoride  |            |        |              |
(as Se)...............|  7783-79-1 |   0.05 |        0.4   | ....
Silica, amorphous,     |            |        |              |
precipitated and gel..|112926-00-8 |   2    |       2      |   2
Silica, amorphous,     |            |        |              |
diatomaceous earth,   |            |        |              |
containing less than  |            |        |              |
1% crystalline silica | 61790-53-2 |   2    |       2      |   2
Silica, crystalline    |            |        |              |
cristobalite,         |            |        |              |
respirable dust.......| 14464-46-1 |   2    |       2      |   2
Silica, crystalline    |            |        |              |
quartz, respirable    |            |        |              |
dust..................| 14808-60-7 |   2    |       2      |   2
Silica, crystalline    |            |        |              |
tripoli (as quartz),  |            |        |              |
respirable dust.......|  1317-95-9 |   2    |       2      |   2
Silica, crystalline    |            |        |              |
tridymite,            |            |        |              |
respirable dust.......| 15468-32-3 |   2    |       2      |   2
Silica, fused,         |            |        |              |
respirable dust.......| 60676-86-0 |   2    |       2      |   2
Silicates (less than 1%|            |        |              |
crystalline silica)   |            |        |              |
Mica (respirable      |            |        |              |
dust).................| 12001-26-2 |   2    |       2      |   2
Soapstone, total dust | .......... |   2    |       2      |   2
Soapstone, respirable |            |        |              |
dust..................| .......... |   2    |       2      |   2
Talc (containing      |            |        |              |
asbestos).............| .......... |   3    |       3      |   3
Talc (containing no    |            |        |              |
asbestos),            |            |        |              |
respirable dust.......| 14807-96-6 |   2    |       2      |   2
Tremolite.............|            |   3    |       3      |   3
Silicon................|  7440-21-3 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Silicon carbide........|   409-21-2 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Silver, metal and      |            |        |              |
soluble compounds     |            |        |              |
(as Ag)...............|  7440-22-4 | ...... |        0.01  | ....
Soapstone;             |            |        |              |
see Silicates.........|            |        |              |
Sodium fluoroacetate...|    62-74-8 | ...... |        0.05  |  X
Sodium hydroxide.......|  1310-73-2 | ...... |        2     | ....
Starch.................|  9005-25-8 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Stibine................|  7803-52-3 |   0.1  |        0.5   | ....
Stoddard solvent.......|  8052-41-3 | 200    |     1150     | ....
Strychnine.............|    57-24-9 | ...... |        0.15  | ....
Styrene................|   100-42-5 | 100    |      420     |  50
Sucrose................|    57-50-1 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Sulfur dioxide.........|  7446-09-5 |   5    |       13     | ....
Sulfur hexafluoride....|  2551-62-4 | 1000   |     6000     | ....
Sulfuric acid..........|  7664-93-9 | ...... |        1     | ....
Sulfur monochloride....| 10025-67-9 |   1    |        6     | ....
Sulfur pentafluoride...|  5714-22-7 |   0.025|        0.25  | ....
Sulfuryl fluoride......|  2699-79-8 |   5    |       20     | ....
Systox;  see Demeton...|            |        |              |
2,4,5-T (2,4,5-tri-    |            |        |              |
chlorophenoxyacetic   |            |        |              |
acid).................|    93-76-5 | ...... |       10     | ....
Talc;  see Silicates...|            |        |              |
Tantalum, metal and    |            |        |              |
oxide dust............|  7440-25-7 | ...... |        5     | ....
TEDP (Sulfotep)........|  3689-24-5 | ...... |        0.2   |  X
Teflon decomposition   |            |        |              |
products..............|            |        |       A2     |
Tellurium and          |            |        |              |
compounds (as Te).....| 13494-80-9 | ...... |        0.1   | ....
Tellurium hexafluoride |            |        |              |
(as Te)...............|  7783-80-4 |   0.02 |        0.2   | ....
Temephos...............|  3383-96-8 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
TEPP (Tetraethyl       |            |        |              |
pyrophosphaate).......|   107-49-3 | ...... |        0.05  |  X
Terphenylis............| 26140-60-3 | (C)1   |     (C)9     | ....
1,1,1,2-Tetrachloro-2, |            |        |              |
2-difluoroethane......|    76-11-9 |  500   |     4170     | ....
1,1,2,2-Tetrachloro-1, |            |        |              |
2-difluoroethane......|    76-12-0 |  500   |     4170     | ....
1,1,2,2-Tetrachloro-   |            |        |              |
ethane................|    79-34-5 |   5    |       35     |  X
Tetrachoroethylene;    |            |        |              |
see Perchloroethylene |            |        |              |
Tetrachloromethane; see|            |        |              |
Carbon tetrachloride..|            |        |              |
Tetrachloronaphthalene.|  1335-88-2 | ...... |        2     |  X
Tetraethyl lead (as Pb)|    78-00-2 | ...... |        0.1   |  X
Tetrahydrofuran........|   109-99-9 |  200   |      590     | ....
Tetramethyl lead,      |            |        |              |
(as Pb)...............|    75-74-1 | ...... |        0.15  |  X
Tetramethyl            |            |        |              |
succinonitrile........|  3333-52-6 |   0.5  |        3     |  X
Tetranitromethane......|   509-14-8 |   1    |        8     | ....
Tetryl (2,4,6-Trinitro-|            |        |              |
phenylmethyl-         |            |        |              |
nitramine)............|   479-45-8 | ...... |        1.5   |  X
Thallium, soluble      |            |        |              |
compounds (as Tl).....|  7440-28-0 | ...... |        0.1   |  X
4,4'-Thiobis(6-tert,   |            |        |              |
Butyl-m-cresol).......|    96-69-5 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Thiram.................|   137-26-8 | ...... |        5     | ....
Tin, inorganic         |            |        |              |
compounds (except     |            |        |              |
oxides) (as Sn).......|  7440-31-5 | ...... |        2     | ....
Tin, organic compounds |            |        |              |
(as Sn)...............|  7440-31-5 | ...... |        0.1   | ....
Tin oxide (as Sn)......| 21651-19-4 | ...... |    .......   | ....
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Titanium dioxide.......| 13463-67-7 |        |              |
Total dust............|            | ...... |       15     | ....
Toluene................|   108-88-3 |  200   |      750     |  100
Toluene-2,             |            |        |              |
4-diisocyanate (TDI)..|   584-84-9 |(C)0.02 |     (C)0.14  | ....
o-Toluidine............|    95-53-4 |   5    |       22     |  X
Toxaphene;  see        |            |        |              |
Chlorinated camphene..|            |        |              |
Tremolite;             |            |        |              |
see Silicates.........|            |        |              |
Tributyl phosphate.....|   126-73-8 | ...... |        5     | ....
1,1,1-Trichloroethane; |            |        |              |
see Methyl chloroform |            |        |              |
1,1,2-Trichloroethane..|    79-00-5 |  10    |       45     |  X
Trichloroethylene......|    79-01-6 | 100    |      535     | ....
Trichloromethane;      |            |        |              |
see Chloroform        |            |        |              |
Trichloronaphthalene...|  1321-65-9 | ...... |        5     |  X
1,2,3-Trichloropropane.|    96-18-4 |  50    |      300     | ....
1,1,2-Trichloro-1,2,   |            |        |              |
2-trifluoroethane.....|    76-13-1 | 1000   |     7600     | ....
Triethylamine..........|   121-44-8 |   25   |      100     | ....
Trifluorobromomethane..|    75-63-8 | 1000   |     6100     | ....
Trimethyl benzene......| 25551-13-7 |   25   |      120     | ....
2,4,6-Trinitrophenyl;  |            |        |              |
see Picric acid.......|            |        |              |
2,4,6-Trinitrophenyl-  |            |        |              |
methyl nitramine;     |            |        |              |
see Tetryl............|            |        |              |
2,4,6-Trinitrotoluene  |            |        |              |
(TNT).................|   118-96-7 | ...... |        1.5   |  X
Triorthocresyl         |            |        |              |
phosphate.............|    78-30-8 | ...... |        0.1   | ....
Triphenyl phosphate....|   115-86-6 | ...... |        3     | ....
Tungsten (as W)........|  7440-33-7 |        |              |
Insoluble compounds...|            | ...... |        5     | ....
Soluble compounds.....|            | ...... |        1     | ....
Turpentine.............|  8006-64-2 |  100   |      560     | ....
Uranium (as U).........|  7440-61-1 |        |              |
Soluble compounds.....|            | ...... |        0.2   | ....
Insoluble compounds...|            | ...... |        0.2   | ....
Respirable dust       |            |        |              |
(as V2O5).............|            | ...... |     (C)0.5   | ....
Fume (as V2O5)........|            | ...... |     (C)0.1   | ....
Vegetable oil mist.....|            |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Vinyl benzene;         |            |        |              |
see Styrene...........|            |        |              |
Vinyl chloride;        |            |        |              |
see 1915.1017.........|    75-01-4 |        |              |
Vinyl cyanide;         |            |        |              |
see Acrylonitrile     |            |        |              |
Vinyl toluene..........| 25013-15-4 |  100   |      480     | ....
Warfarin...............|    81-81-2 | ...... |        0.1   | ....
Xylenes                |            |        |              |
(o-, m-, p-isomers)...|  1330-20-7 |  100   |      435     | ....
Xylidine...............|  1300-73-8 |    5   |       25     |  X
Yttrium................|  7440-65-5 | ...... |        1     | ....
Zinc chloride fume.....|  7646-85-7 | ...... |        1     | ....
Zinc oxide fume........|  1314-13-2 | ...... |        5     | ....
Zinc oxide.............|  1314-13-2 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Zinc stearate..........|   557-05-1 |        |              |
Total dust............|            | ...... |       15     | ....
Respirable fraction...|            | ...... |        5     | ....
Zirconium compounds    |            |        |              |
(as Zr)...............|  7440-67-7 | ...... |        5     |
_______________________|____________|________|______________|______

MINERAL DUSTS
____________________________________________________________________
|
Substance                                |      mppcfj
_____________________________________________|______________________
|
SILICA:                                      |
Crystalline                                 |
Quartz.  Threshold limit calculated from the |
formula.....................................|         250k
|_____________________
|  percent SiO2+5
Cristobalite.                                |
Amorphous, including natural diatomaceous   |
earth.....................................|          20
SILICATES (less than 1 percent crystalline   |
silica)                                     |
Mica........................................|          20
Portland cement.............................|          50
Soapstone...................................|          20
Talc (non-asbestiform)......................|          20
Talc (fibrous), use asbestos limit..........|          --
Graphite (natural)...........................|          15
_____________________________________________|_____________________
|
Inert or Nuisance Particulates:(m)           | 50 (or 15 mg/m3
|   whichever is
|   the smaller) of
|   total dust less
|   than 1 percent
|   SiO2
Conversion factors.                         |
mppcf X 35.3 = million particles per cubic   |
meter = particles per c.c.             |
_____________________________________________|_____________________
1 [Reserved]
2 See Mineral Dusts Table.
3 Use Asbestos Limit § 1915.1001.
4 See 1915.1001
* The PELS are 8-hour TWAs unless otherwise noted; a (C)
designation denotes a ceiling limit. They are to be determined from breathing-zone
air samples.
a Parts of vapor or gas per million parts of contaminated
air by volume at 25[deg] C and 760 torr.
b Milligrams of substance per cubic meter of air. When
entry is in this column only, the value is exact; when listed with a ppm entry,
it is approximate.
c [Reserved]
d The CAS number is for information only. Enforcement is
based on the substance name. For an entry covering more than one metal compound,
measured as the metal, the CAS number for the metal is given -- not CAS numbers
for the individual compounds.
e [Reserved]
f [Reserved]
g For sectors excluded from 1915.1028 the limit is 10 ppm
TWA.
h Where OSHA has published a proposal for a substance but
has not issued a final rule, the proposal is referenced and the
existing limit is published.
i [Reserved]
j Millions of particles per cubic foot of air, based on
impinger samples counted by light-field techniques.
k The percentage of crystalline silica in the formula is
the amount determined from airborne samples, except in those
instances in which other methods have been shown to be applicable.
l [Reserved]
m Covers all organic and inorganic particulates not
otherwise regulated.  Same as Particulates Not Otherwise Regulated.
n If the exposure limit in 1915.1026 is stayed or is not
otherwise in effect, the TLV is a ceiling of 0.1 µg/m3 (as CrO3).
o if the exposure limit in 1915.1026 is stayed or is otherwise not
in effect, the TLV is 0.1 µg/m3 (as CrO3) as an 8-hour TWA.
The 1970 TLV uses letter designations instead of a numerical value
as follows:
A1 [Reserved]
A2 Polytetrafluoroethylene decomposition products.
Because these products decompose in part by hydrolysis in alkaline
solution, they can be quantitatively determined in air as fluoride to
provide an index of exposure.  No TLV is recommended pending
determination of the toxicity of the products, but air concentrations
should be minimal.
A3 Gasoline and/or Petroleum distillates.  The
composition of these materials varies greatly and thus a single TLV
for all types of these materials is no longer applicable.  The
content of benzene, other aromatics and additives should be
determined to arrive at the appropriate TLV.
E Simple asphyxiants.  The limiting factor is the
available oxygen which shall be at least 18 percent and be within the
requirements addressing explosion in subpart B of part 1915.

```
[58 FR 35514, July 1, 1993; 61 FR 56746, Nov. 4, 1996; 62 FR 1493, Jan. 10, 1997; 67 FR 44545, July 3, 2002; 71 FR 10377, Feb. 28, 2006; 76 FR 80740, Dec. 27, 2011]