DEPARTMENT OF LABOR AND ECONOMIC OPPORTUNITY  
DIRECTOR’S OFFICE  
GENERAL INDUSTRY SAFETY AND HEALTH STANDARD  
(By authority conferred on the director of the department of labor and economic  
opportunity by sections 14, 16, 19, 21, and 24 of the Michigan occupational safety and  
health act, 1974 PA 154, MCL 408.1014, 408.1016, 408.1019, 408.1021, and 408.1024,  
and Executive Reorganization Order Nos. 1996-1, 1996-2, 2003-1, 2008-4, 2011-4, and  
2019-3, MCL 330.3101, 445.2001, 445.2011, 445.2025, 445.2030, and 125.1998)  
PART 301. AIR CONTAMINANTS FOR GENERAL INDUSTRY  
R 325.51101 Scope, application, and availability of standards.  
Rule 1. (1) These rules do not apply to the following types of employment:  
(a) Agriculture.  
(b) Domestic.  
(c) Mining.  
(d) Construction.  
(2) Exposure to air contaminants in construction work is covered by Construction Safety  
and Health Standard Part 601. Air Contaminants for Construction.”  
(3) The following Michigan Occupational Safety and Health Administration (MIOSHA)  
standards are referenced in these rules. Up to 5 copies of these standards may be  
obtained at no charge from the Michigan Department of Labor and Economic  
Opportunity, MIOSHA Regulatory Services Section, 530 West Allegan Street, P.O. Box  
30643, Lansing, Michigan, 48909-8143 or via the internet at the following website:  
www.michigan.gov/mioshastandards. For quantities greater than 5, the cost, as of the  
time of adoption of these rules, is 4 cents per page.  
(a) General Industry Safety and Health Standard Part 302. Vinyl Chloride,”  
R 325.51401 to R 325.51414.  
(b) General Industry Safety and Health Standard Part 303. Methylenedianiline (MDA)  
in General Industry,” R 325.50051 to R 325.50076.  
(c) General Industry and Construction Safety and Health Standard Part 304. “Ethylene  
Oxide,” R 325.51151 to R 325.51177.  
(d) Occupational Health Standard Part 305. “Asbestos for General Industry,”  
R 325.51311 to R 325.51312.  
(e) General Industry and Construction Safety and Health Standard Part 306.  
Formaldehyde,” R 325.51451 to R 325.51477.  
(f) General Industry and Construction Safety and Health Standard Part 307.  
Acrylonitrile,” R 325.51501 to R 325.51527.  
(g) General Industry and Construction Safety and Health Standard Part 308. “Inorganic  
Arsenic,” R 325.51601 to R 325.51628.  
Page 1  
(h) General Industry Safety and Health Standard Part 309. “Cadmium in General  
Industry,” R 325.51851 to R 325.51886.  
(i) General Industry Safety and Health Standard Part 310. “Lead in General Industry,”  
R 325.51901 to R 325.51958.  
(j) General Industry and Construction Safety and Health Standard Part 311. “Benzene,”  
R 325.77101 to R 325.77115.  
(k) Occupational Health Standard Part 312. “1,3-Butadiene,” R 325.50091 to  
R 325.50093.  
(l) Occupational Health Standard Part 313. “Methylene Chloride,” R 325.51651 to  
R 325.51653.  
(m) General Industry and Construction Safety and Health Standard Part 314. “Coke  
Oven Emissions,” R 325.50100 to R 325.50136.  
(n) Occupational Health Standard Part 315. “Chromium (VI) in General Industry,”  
R 325.50141 to R 325.50143.  
(o) General Industry Safety and Health Standard Part 340. “Beryllium,R 325.34001  
to R 325.34010.  
(p) General Industry Safety and Health Standard Part 350. “Carcinogens,”  
R 325.35001 to R 325.35011.  
(q) Occupational Health Standard Part 451. “Respiratory Protection,” R 325.60051 to  
R 325.60052.  
(r) General Industry Safety and Health Standard Part 590. “Silica in General Industry,”  
R 325.59001 to R 325.59015.  
(s) Construction Safety and Health Standard Part 601. “Air Contaminants for  
Construction,” R 325.60151 to R 325.60161.  
History: 1990 AACS; 2013 AACS; 2017 AACS; 2019 AACS.  
R 325.51101a Rescinded.  
History: 2013 AACS; 2017 AACS; 2019 AACS.  
R 325.51102 Definitions.  
Rule 2. (1) "Ceiling" means the employee's exposure that shall not be exceeded during  
any part of the workday. If instantaneous monitoring is not feasible, then the ceiling shall  
be assessed as a 15-minute, time-weighted average exposure that shall not be exceeded  
during any part of the working day.  
(2) "Skin designation" means those substances so indicated that have toxic effects due  
to absorption through an employee's skin.  
(3) "Short-term exposure limit (STEL)" means the employee's 15-minute, time-  
weighted average exposure that shall not be exceeded at any time during a workday,  
unless another time limit is specified in a parenthetical notation below the limit. If  
another time period is specified, then the time-weighted average exposure over that time  
limit shall not be exceeded at any time during the workday.  
(4) "Time-weighted average (TWA)" means the employee's average airborne exposure  
in any 8-hour workshift of a 40-hour workweek that shall not be exceeded.  
Page 2  
(5) The terms "substance" and "air contaminant" are equivalent in meaning for purposes  
of these rules.  
History: 1990 AACS; 2001 AACS; 2017 AACS.  
R 325.51103 Exposure limits.  
Rule 3. An employer shall ensure that an employee exposure to any substance listed in  
tables G-1-A or G-2 in R 325.51108 is limited in accordance with the requirements of all  
of the following provisions:  
(a) With respect to table G-1-A, all of the following provisions apply:  
(i) Removed (May 9, 2001).  
(ii) Removed (May 20, 2001).  
(iii) An employee's exposure to any substance listed in table G-1-A shall not exceed the  
time-weighted average (TWA) limit, short-term exposure limit (STEL) and ceiling limit  
specified for that substance in table G-1-A.  
(iv) To prevent or reduce skin absorption, an employee's skin exposure to substances  
listed in table G-1-A with an "X" in the skin designation column following the substance  
name shall be prevented or reduced to the extent necessary through the use of gloves,  
coveralls, goggles, or other appropriate personal protective equipment, engineering  
controls, or work practices.  
(v) An employee shall not be exposed to air concentrations between the TWA and  
STEL limits more than 4 times in a workshift and such exposures shall be no less than 60  
minutes apart.  
(b) With respect to table G-2, all of the following provisions apply:  
(i) An employee's exposure to any substance listed in table G-2 in any 8-hour workshift  
of a 40-hour workweek shall not exceed the 8-hour, time-weighted average limit given  
for that substance in table G-2.  
(ii) An employee's exposure to a substance listed in table G-2 shall not exceed, at any  
time during an 8-hour workshift, the acceptable ceiling concentration limit given for the  
substance in the table, except for a period of time and up to a concentration that does not  
exceed the maximum duration and concentration allowed in the column under  
"Acceptable maximum peak above the ceiling concentration for an 8-hour workshift."  
For example, during an 8-hour workshift, an employee may be exposed to a  
concentration of Substance A (with a 10 parts of the substance per million parts of air  
(ppm) TWA, 25 ppm ceiling and 50 ppm peak) above 25 ppm (but not above 50 ppm)  
only for a maximum period of 10 minutes. Such an exposure shall be compensated for by  
exposures to concentrations less than 10 ppm so the cumulative exposure for the entire 8-  
hour workshift does not exceed a time-weighted average of 10 ppm.  
(iii) If a substance is preceded by an "S", then an employer shall take the necessary  
precautions to prevent an employee from absorbing the substance through his or her skin.  
History: 1990 AACS; 2001 AACS; 2017 AACS.  
R 325.51104 Computation formulae.  
Page 3  
Rule 4. The computation formulas that apply to employee exposure to 1 or more  
substances that have an 8-hour, time-weighted average listed in table G-1-A or G-2 to  
determine whether an employee is exposed in excess of the exposure limit are as follows:  
(a) An employer shall compute the cumulative exposure for multiple exposures to a  
single substance for an 8-hour workshift as follows:  
E = (C1T1 + C2T2 + ... CnTn) ÷ 8 hours  
Where:  
E is the cumulative exposure for an 8-hour workshift.  
C1 is the substance concentration during the first period of time "T" where the  
concentration remains constant.  
C2 is the substance concentration during the second period of time "T" where the  
concentration remains constant.  
T is the period of time in hours for which the substance concentration C remains  
constant.  
The value of E shall not exceed the 8-hour, time-weighted average limit for the  
substance as specified in table G-1-A or G-2.  
To illustrate the formula for a cumulative exposure to a single substance, assume that  
Substance A has an 8-hour, time-weighted average exposure limit of 100 ppm noted in  
table G-1-A. Assume that an employee is subject to the following exposures over an 8-  
hour workshift:  
Two hours' exposure at 150 ppm  
Two hours' exposure at 75 ppm  
Four hours' exposure at 50 ppm  
Substituting this information into the formula:  
E = [(150 ppm X 2 hrs) + (75 ppm X 2 hrs) + (50 ppm X 4 hrs)] ÷ 8 hrs  
E = [300 ppm·hrs + 150 ppm·hrs + 200 ppm·hrs] ÷ 8 hrs  
E = 650 ppm·hrs ÷ 8 hrs = 81.25 ppm  
Since the cumulative exposure of 81.25 ppm is less than the exposure limit of 100 ppm,  
then the employee's 8-hour workshift exposure is acceptable.  
(b) An employer shall compute the equivalent exposure for a mixture of air  
contaminants for an 8-hour workshift as follows:  
Em = (C1 ÷ L1 + C2 ÷ L2) + ... (Cn ÷ Ln)  
Where:  
Em is the equivalent exposure to the mixture of air contaminants during an 8-hour  
workshift.  
C1 is the average 8-hour concentration of the first substance.  
Page 4  
C2 is the average 8-hour concentration of the second substance.  
L is the 8-hour, TWA exposure limit for that particular substance. The value of Em  
shall not exceed a value of one (1.0).  
To illustrate the formula for a mixture of air contaminants, assume the following  
exposures:  
Average concentration of 8-hour 8-hour TWA exposure  
Substances in mixture  
exposure (C)  
500 ppm  
limit (L)  
Substance A  
Substance B  
Substance D  
1,000 ppm  
45 ppm  
40 ppm  
200 ppm  
200 ppm  
Substituting this information into the formula:  
EM = (500 ppm ÷ 1,000 ppm) + (45 ppm ÷ 200 ppm) + (40 ppm ÷ 200 ppm)  
Em = 0.500 + 0.225 + 0.200  
Em = 0.925  
Since the value of Em did not exceed one (1.0), the employee's 8-hour workshift  
exposure to the mixture of air contaminants is acceptable.  
History: 1990 AACS; 2001 AACS; 2017 AACS.  
R 325.51105 Methods of compliance.  
Rule 5. To achieve compliance with the provisions of R 325.51103 and R 325.51104,  
administrative or engineering controls must first be determined and implemented if  
feasible. If such controls are not feasible to achieve full compliance, then personal  
protective equipment or any other protective measures must be used to keep the  
employee’s exposure to air contaminants within the exposure limits prescribed in these  
rules. Any equipment and technical measures used for this purpose must be approved for  
each particular use by a competent industrial hygienist or other technically qualified  
person. If a respirator is used, its use must comply with the provisions of Occupational  
Health Standard Part 451. “Respiratory Protection.”  
History: 1990 AACS; 2001 AACS; 2013 AACS; 2019 AACS.  
R 325.51106 Rescinded.  
History: 1990 AACS; 2001 AACS.  
Page 5  
R 325.51107 Stay of enforcement.  
Rule 7. Enforcement of the limits are indefinitely stayed for the following  
substances until the United States department of labor, occupational safety and  
health administration (OSHA) publishes in the Federal Register a notice that a  
sampling and analytical technique is available:  
(a) Aluminum alkyls.  
(b) Ethylidine norbornene.  
(c) Hexafluoroacetone.  
(d) Mercury (alkyl compounds).  
(e) Oxygen difluoride.  
(f) Phenylphosphine.  
(g) Sulfur pentafluoride.  
History: 1990 AACS.  
Page 6  
R 325.51108 Tables.  
Rule 8. Tables G-1-A and G-2 read as follows:  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Abate  
100  
10  
15  
180  
25  
150  
270  
5
Acetaldehyde  
Acetic acid  
Acetic anhydride  
Acetone  
75-07-0  
64-19-7  
108-24-7  
67-64-1  
75-05-8  
20  
750  
40  
1800  
70  
1000  
60  
2400  
105  
Acetonitrile  
2-Acetylaminofluorine; see GI Part 350.  
CarcinogensF  
53-96-3  
Acetylene dichloride; see 1,2-Dichloroethylene  
Acetylene tetrabromide  
Acetylsalicylic acid (Aspirin)  
Acrolein  
79-27-6  
50-78-2  
107-02-8  
79-06-1  
79-10-7  
1
14  
5
x
x
0.1  
0.25  
0.03  
30  
0.3  
0.8  
Acrylamide  
Acrylic acid  
10  
Acrylonitrile; see GI & CS Part 307. AcrylonitrileF  
107-13-1  
2
4.34  
10  
21.7  
Page 7  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Aldrin  
309-00-2  
107-18-6  
107-05-1  
106-92-3  
2179-59-1  
2
1
5
2
0.25  
5
4
x
x
Allyl alcohol  
Allyl chloride  
10  
6
3
2
Allyl glycidyl ether (AGE)  
Allyl propyl disulfide  
22  
12  
10  
3
44  
18  
α Alumina (aluminum oxide)  
Respirable fraction  
Total dust  
1344-28-1  
5
10  
Aluminum (as Al)  
Alkyls  
2
Metal  
Respirable dust  
Total dust  
Pyro powders  
Soluble salts  
Welding fumes*  
5
15  
5
2
5
7429-90-5  
92-67-1  
4-Aminodiphenyl; see GI Part 350. CarcinogensF  
2-Aminoethanol; see Ethanolamine  
2-Aminopyridine  
Amitrole  
504-29-0  
61-82-5  
0.5  
2
0.2  
Ammonia  
7664-41-7  
35  
24  
Page 8  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Ammonium chloride fume  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
12125-02-9  
10  
20  
Ammonium sulfamate  
Respirable dust  
Total dust  
7773-06-0  
5
10  
n-Amyl acetate  
628-63-7  
626-38-0  
62-53-3  
100  
125  
2
525  
650  
8
x
x
sec-Amyl acetate  
Aniline and homologues  
Anisidine (o- and p-isomers)  
Antimony and compounds (as Sb)  
ANTU (alpha-naphthylthiourea)  
Arsenic, organic compounds (as As)  
29191-52-4  
7440-36-0  
86-88-4  
0.5  
0.5  
0.3  
0.5  
7440-38-2  
Arsenic, inorganic compounds (as As); see GI &  
CS Part 308. Inorganic ArsenicF  
7440-38-2  
7784-42-1  
0.01  
0.2  
Arsine  
0.05  
TWA  
STELD  
Asbestos; see OH Part 305. Asbestos for General  
IndustryF  
Varies  
0.1f/cc  
mg/m3C  
Skin  
Designation  
ppmB  
ppmB  
mg/m3C  
ppmB mg/m3C  
Atrazine  
1912-24-9  
5
Page 9  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Azinphos-methyl  
86-50-0  
0.2  
0.5  
x
Barium, soluble compounds (as Ba)  
7440-39-3  
Barium sulfate  
Respirable dust  
Total dust  
7727-43-7  
5
10  
Benomyl  
Respirable dust  
Total dust  
17804-35-2  
5
10  
BenzeneE; see GI & CS Part 311. BenzeneF and  
table G-2 for limits applicable in the operations  
or sectors excluded in R 325.77101E  
71-43-2  
92-87-5  
1
3.19  
5
15.97  
Benzidine; see GI Part 350. CarcinogensF  
p-Benzoquinone; see Quinone  
Benzo(a)pyrene; see Coal tar pitch volatiles  
Benzoyl peroxide  
Benzyl chloride  
94-36-0  
5
5
100-44-7  
1
0.0002  
0.002  
(0.2 μg/m3)  
(2.0 μg/m3)  
Beryllium and beryllium compounds (as Be) see  
GI Part 340. Beryllium  
7440-41-7  
Page 10  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Biphenyl; see Diphenyl  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Bismuth telluride, Undoped  
Respirable dust  
1304-82-1  
5
15  
Total dust  
Bismuth telluride, Se-doped  
5
Borates, Tetra, Sodium Salts  
Anhydrous  
1330-43-4  
1303-96-4  
12179-04-3  
10  
10  
10  
Decahydrate  
Pentahydrate  
Boron oxide, Total dust  
Boron tribromide  
Boron trifluoride  
Bromacil  
1303-86-2  
10294-33-4  
7637-07-2  
314-40-9  
10  
2
1
1
10  
3
1
10  
0.7  
0.7  
5
Bromine  
7726-95-6  
7789-30-2  
75-25-2  
0.1  
0.1  
0.5  
0.3  
Bromine pentafluoride  
Bromoform  
1,3-Butadiene; see OH Part 312. 1,3-ButadieneF  
106-99-0  
106-97-8  
1
2.2  
5
11.1  
Butane  
800  
1900  
Butanethiol; see Butyl mercaptan  
Page 11  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
2-Butanone (Methyl ethyl ketone)  
2-Butoxyethanol  
78-93-3  
111-76-2  
123-86-4  
105-46-4  
540-88-5  
141-32-2  
71-36-3  
200  
25  
590  
120  
710  
950  
950  
55  
300  
885  
x
x
x
n-Butyl acetate  
150  
200  
200  
10  
200  
950  
sec-Butyl acetate  
tert-Butyl acetate  
Butyl acrylate  
nButyl alcohol (n-butanol)  
sec-Butyl alcohol (sec-butanol)  
tert-Butyl alcohol (tert-butanol)  
Butylamine  
50  
150  
78-92-2  
100  
100  
305  
300  
75-65-0  
150  
450  
109-73-9  
5
15  
0.005  
tert-Butyl chromate (as Cr+6); see OH Part 315.  
Chromium (VI) in General IndustryF,G  
1189-85-1  
(5 μg/m3)  
x
n-Butyl glycidyl ether (BGE)  
n-Butyl lactate  
2426-08-6  
138-22-7  
109-79-5  
89-72-5  
25  
5
135  
25  
x
Butyl mercaptan  
0.5  
5
1.5  
30  
o-sec-Butylphenol  
p-tert-Butyltoluene  
98-51-1  
10  
60  
20  
120  
Page 12  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
7440-43-9  
ppmB  
ppmB  
ppmB mg/m3C  
Cadmium; see GI Part 309. Cadmium in General  
IndustryF  
0.005  
Calcium carbonate,  
Respirable dust  
Total dust  
1317-65-3  
5
15  
Calcium cyanamide  
Calcium hydroxide  
Calcium oxide  
156-62-7  
1305-62-0  
1305-78-8  
0.5  
5
5
Calcium silicate,  
Respirable dust  
Total dust  
1344-95-2  
5
15  
Calcium sulfate,  
Respirable dust  
Total dust  
7778-18-9  
76-22-2  
5
15  
Camphor, synthetic  
2
Caprolactam,  
Dust  
105-60-2  
5
1
20  
10  
3
40  
Vapor  
Captafol (DifolatanR)  
2425-06-1  
133-06-2  
63-25-2  
0.1  
5
Captan  
Carbaryl (SevinR)  
Carbofuran (FuradanR)  
5
1563-66-2  
0.1  
Page 13  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Carbon black  
1333-86-4  
124-38-9  
3.5  
30,00  
0
Carbon dioxide  
5,000  
9,000  
54,000  
Carbon disulfide  
75-15-0  
630-08-0  
558-13-4  
56-23-5  
4
35  
0.1  
2
12  
40  
12  
36  
200  
229  
x
x
x
Carbon monoxide  
Carbon tetrabromide  
1.4  
12.6  
5
0.3  
4
Carbon tetrachloride (Tetrachloromethane)  
Carbonyl fluoride  
353-50-4  
120-80-9  
2
5
15  
Catechol (Pyrocatechol)  
5
20  
Cellulose,  
Respirable dust  
Total dust  
9004-34-6  
5
15  
Cesium hydroxide  
21351-79-1  
57-74-9  
2
1
x
x
Chlordane  
0.5  
0.5  
Chlorinated camphene (Toxaphone)  
8001-35-2  
55720-99-5  
or  
Chlorinated diphenyl oxide  
0.5  
31242-93-0  
Chlorine  
7782-50-5  
0.5  
0.1  
1.5  
0.3  
1
3
Chlorine dioxide  
10049-04-4  
0.3  
0.9  
Page 14  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Chlorine trifluoride  
Chloroacetaldehyde  
7790-91-2  
107-20-0  
532-27-4  
79-04-9  
0.1  
1
0.4  
3
x
2-Chloroacetophenone (Phenacyl chloride)  
Chloroacetyl chloride  
0.5  
0.5  
75  
0.3  
0.2  
350  
Chlorobenzene  
108-90-7  
2698-41-1  
74-97-5  
o-Chlorobenzylidene malononitrile  
Chlorobromomethane  
0.05  
0.4  
200  
1050  
2-Chloro-1,3-butadiene; see β -Chloroprene  
Chlorodifluoromethane  
75-45-6  
1000  
3500  
1
x
x
Chlorodiphenyl (42% Chlorine) (PCB)  
Chlorodiphenyl (54% Chlorine) (PCB)  
1-Chloro-2,3-epoxy propane; see Epichlorohydrin  
2-Chloroethanol; see Ethylene chlorohydrin  
Chloroethylene; see Vinyl chloride  
Chloroform (Trichloromethane)  
53469-21-9  
11097-69-1  
0.5  
67-66-3  
2
9.78  
bis (Chloromethyl) ether; GI Part 350.  
CarcinogensF  
542-88-1  
Page 15  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
107-30-2  
ppmB  
ppmB  
ppmB mg/m3C  
Chloromethyl methyl ether; see GI Part 350.  
CarcinogensF  
1-Chloro-1-nitropropane  
Chloropentafluoroethane  
Chloropicrin  
600-25-9  
76-15-3  
4
1000  
0.1  
10  
10  
6320  
0.7  
x
76-06-2  
beta-Chloroprene  
o-Chlorostyrene  
126-99-8  
2039-87-4  
95-49-8  
35  
50  
285  
250  
75  
428  
o-Chlorotoluene  
50  
2-Chloro-6-(trichloromethyl) pyridine,  
Respirable dust  
1929-82-4  
2921-88-2  
5
15  
Total dust  
Chlorpyrifos  
0.2  
x
Chromic acid and chromates (as Cr+6); see OH  
Part 315. Chromium (VI) in General  
IndustryF,G  
0.005  
Varies with  
compound  
(5 μg/m3)  
Chromium (II) compounds (as Cr)  
Chromium (III) compounds (as Cr)  
7440-47-3  
7440-47-3  
0.5  
0.5  
Chromium (VI) compounds; see OH Part 315.  
Chromium (VI) in General IndustryF,G  
Varies with  
compound  
(5 μg/m3)  
Chromium metal (as Cr)  
7440-47-3  
1
Page 16  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Chrysene; see Coal tar pitch volatile  
Clopidol  
Respirable dust  
Total dust  
2971-90-6  
5
15  
Coal dust (less than 5% SiO2) Respirable dust  
2
Coal dust (greater than or equal to 5% SiO2),  
Respirable dust  
0.1  
Coal tar pitch volatile (as benzene solubles)  
anthracene, BaP, phenanthrene, acridine,  
crysene, pyrene  
65996-93-2  
0.2  
Cobalt metal, dust, and fume (as Co)  
Cobalt carbonyl (as Co)  
7440-48-4  
10210-68-1  
16842-03-8  
0.05  
0.1  
Cobalt hydrocarbonyl (as Co)  
0.1  
Coke oven emissions; see GI & CS Part 314. Coke  
Oven EmissionsF  
0.15  
(150 μg/m3)  
Copper,  
Dusts and mists (as Cu)  
Fume (as Cu)  
7440-50-8  
1
0.1  
Cotton dust (raw)  
1
Crag herbicide (Sesone)  
Total dust  
136-78-7  
10  
5
Respirable fraction  
Page 17  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
1319-77-3  
ppmB  
ppmB  
ppmB mg/m3C  
Cresol, all isomers  
Crotonaldehyde  
5
2
22  
6
x
123-73-9  
4170-30-3  
Crufomate  
Cumene  
299-86-5  
98-82-8  
50  
5
245  
2
x
Cyanamide  
420-04-2  
Varies with  
compound  
Cyanides (as CN)  
5
x
Cyanogen  
460-19-5  
506-77-4  
110-82-7  
108-93-0  
108-94-1  
110-83-8  
108-91-8  
121-82-4  
542-92-7  
287-92-3  
10  
20  
0.3  
0.6  
x
x
x
Cyanogen chloride  
Cyclohexane  
Cyclohexanol  
Cyclohexanone  
Cyclohexene  
Cyclohexylamine  
Cyclonite  
300  
50  
25  
300  
10  
1050  
200  
100  
1015  
40  
1.5  
Cyclopentadiene  
Cyclopentane  
75  
600  
200  
1720  
Page 18  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Cyhexatin  
13121-70-5  
94-75-7  
5
x
x
2,4-D (Dichlorophenoxyacetic acid)  
10  
0.3  
0.1  
Decaborane  
17702-41-9  
8065-48-3  
0.05  
0.15  
0.9  
Demeton (SystoxR)  
Diacetone alcohol  
123-42-2  
50  
240  
(4-Hydroxy-4-methyl-2-pentanone)  
1,2-Diaminoethane; see Ethylenediamine  
Diazinon  
333-41-5  
334-88-3  
19287-45-7  
102-81-8  
107-66-4  
84-74-2  
0.2  
0.1  
2
0.1  
0.4  
0.1  
14  
5
x
Diazomethane  
Diborane  
2-N-Dibutylaminoethanol  
Dibutyl phosphate  
Dibutyl phthalate  
1
2
10  
5
Dichloroacetylene  
o-Dichlorobenzene  
p-Dichlorobenzene  
7572-29-4  
95-50-1  
0.1  
50  
0.4  
300  
106-46-7  
75  
450  
110  
675  
3,3'-Dichlorobenzidine; see GI Part 350.  
CarcinogensF  
91-94-1  
Page 19  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Dichlorodifluoromethane  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
75-71-8  
118-52-5  
50-29-3  
75-34-3  
540-59-0  
111-44-4  
75-43-4  
1000  
4950  
0.2  
1
0.4  
x
x
1,3-Dichloro-5,5-dimethyl hydantoin  
Dichlorodiphenyltri-chloroethane (DDT)  
1,1-Dichloroethane  
100  
200  
5
400  
790  
30  
1,2-Dichloroethylene  
Dichloroethyl ether  
10  
60  
Dichlorofluoromethane  
10  
40  
Dichloromethane; see Methylene chloride  
1,1-Dichloro-1-nitroethane  
1,2-Dichloropropane; see Propylene dichloride  
1,3-Dichloropropene  
594-72-9  
2
10  
542-75-6  
75-99-0  
76-14-2  
62-73-7  
141-66-2  
77-73-6  
1
5
6
x
x
x
2,2-Dichloropropionic acid  
Dichlorotetrafluoroethane  
Dichlorvos (DDVP)  
1
1000  
7000  
1
Dicrotophos  
0.25  
30  
Dicyclopentadiene  
5
Page 20  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Dicyclopentadienyl iron,  
CAS No.A  
102-54-5  
ppmB  
ppmB  
ppmB mg/m3C  
Respirable dust  
Total dust  
5
10  
Dieldrin  
60-57-1  
111-42-2  
109-89-7  
100-37-8  
111-40-0  
3
0.25  
15  
30  
50  
4
x
x
x
Diethanolamine  
Diethylamine  
10  
10  
1
25  
75  
2-Diethylaminoethanol  
Diethylene triamine  
Diethyl ether; see Ethyl ether  
Diethyl ketone  
96-22-0  
84-66-2  
200  
705  
5
Diethyl phthalate  
Difluorodibromomethane  
Diglycidyl ether (DGE)  
Dihydroxybenzene; see Hydroquinone  
Diisobutyl ketone  
75-61-6  
100  
0.1  
860  
0.5  
2238-07-5  
108-83-8  
108-18-9  
25  
5
150  
20  
Diisopropylamine  
x
4-Dimethylaminoazobenzene; see GI Part 350.  
CarcinogensF  
60-11-7  
Dimethoxymethane; see Methylal  
Page 21  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Dimethyl acetamide  
Dimethylamine  
127-19-5  
124-40-3  
10  
10  
35  
18  
x
Dimethylaminobenzene; see Xylidine  
Dimethylaniline (N,N-Dimethylaniline)  
Dimethylbenzene; see Xylene  
121-69-7  
5
25  
10  
50  
x
Dimethyl-1,2-dibromo-2,2-dichloroethyl  
phosphate  
300-76-5  
68-12-2  
3
x
x
Dimethylformamide  
10  
30  
2,6-Dimethyl-4-heptanone; see Diisobutyl ketone  
1,1-Dimethylhydrazine  
57-14-7  
131-11-3  
77-78-1  
148-01-6  
0.5  
1
5
x
x
Dimethylphthalate  
Dimethyl sulfate  
0.1  
0.5  
5
Dinitolmide (3,5-Dinitro-o-toluamide)  
Dinitrobenzene (all isomers)  
1
x
(meta-)  
(ortho)  
(para-)  
99-65-0  
528-29-0  
100-25-4  
Dinitro-o-cresol  
Dinitrotoluene  
534-52-1  
0.2  
1.5  
x
x
25321-14-6  
Page 22  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Dioxane (Diethylene dioxide)  
Dioxathion (Delnav)  
Diphenyl (Biphenyl)  
Diphenylamine  
123-91-1  
78-34-2  
92-52-4  
122-39-4  
25  
90  
0.2  
1
x
x
0.2  
10  
Diphenylmethane diisocyanate; see Methylene bisphenyl isocyanate  
Dipropylene glycol methyl ether  
34590-94-8  
123-19-3  
2768-72-9  
117-81-7  
97-77-8  
100  
50  
600  
235  
0.5  
5
150  
900  
x
x
Dipropyl ketone  
Diquat  
Di-sec-octyl phthalate [Di(2-ethylhexyl) phthalate]  
10  
Disulfiram  
Disulfoton  
2
298-04-4  
0.1  
2,6-Di-tert-butyl-p-cresol (Butylated  
hydroxytoluene)  
128-37-0  
10  
Diuron  
330-54-1  
10  
50  
Divinyl benzene  
1321-74-0  
10  
Emery,  
Respirable dust  
Total dust  
1302-74-5  
115-29-7  
5
10  
Endosulfan  
0.1  
x
Page 23  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Endrin  
72-20-8  
106-89-8  
2104-64-5  
2
0.1  
8
x
x
x
Epichlorohydrin  
EPN  
0.5  
1,2-Epoxypropane; see Propylene oxide  
2,3-Epoxy-1-propanol; see Glycidol  
Ethanethiol; see Ethyl mercaptan  
Ethanolamine  
141-43-5  
563-12-2  
110-80-5  
111-15-9  
141-78-6  
140-88-5  
64-17-5  
3
8
6
15  
x
x
x
x
Ethion  
0.4  
2-Ethoxyethanol (EGEE)  
2-Ethoxyethyl acetate (Cellosolve acetate)  
Ethyl acetate  
200  
100  
400  
5
740  
540  
1400  
20  
Ethyl acrylate  
25  
100  
Ethyl alcohol (Ethanol)  
Ethylamine  
1000  
10  
1900  
18  
75-04-7  
Ethyl amyl ketone (5-Methyl-3-heptanone)  
Ethyl benzene  
541-85-5  
100-41-4  
74-96-4  
25  
130  
435  
890  
100  
200  
125  
250  
545  
1100  
Ethyl bromide  
Page 24  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Ethyl butyl ketone (3-Heptanone)  
Ethyl chloride  
106-35-4  
75-00-3  
50  
1000  
400  
100  
0.5  
10  
230  
2600  
1200  
300  
1
1
3
x
Ethyl ether  
60-29-7  
500  
1500  
Ethyl formate  
109-94-4  
75-08-1  
Ethyl mercaptan  
Ethyl silicate  
78-10-4  
85  
Ethylene chlorohydrin  
Ethylenediamine  
107-07-3  
107-15-3  
106-93-4  
107-06-2  
107-21-1  
628-96-6  
10  
25  
Ethylene dibromide  
Ethylene dichloride  
Ethylene glycol  
See table G-2  
1
4
2
8
50  
125  
x
Ethylene glycol dinitrate (EGDN)  
0.1  
Ethylene glycol methyl acetate (EGME); see Methyl cellosolve acetate  
Ethyleneimine; see GI Part 350. CarcinogensF  
151-56-4  
75-21-8  
Ethylene oxide; see GI & CS Part 304. Ethylene  
OxideF  
1
1.8  
5
9.0  
-
-
-
Ethylidene chloride; see 1,1-Dichloroethane  
Page 25  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Ethylidene norbornene  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
16219-75-3  
100-74-3  
5
3
5
25  
x
x
x
N-Ethylmorpholine  
Fenamiphos  
23  
0.1  
0.1  
0.2  
10  
1
22224-92-6  
115-90-2  
Fensulfothion (Dasanit)  
Fenthion  
55-38-9  
Ferbam, Dust  
14484-64-1  
12604-58-9  
Ferrovanadium dust  
Varies with  
compound  
Fluorides (as F)  
2.5  
Fluorine  
7782-41-4  
75-69-4  
0.1  
0.2  
1000  
5600  
x
Fluorotrichloromethane (Trichlorofluoromethane)  
Fonofos  
944-22-9  
0.1  
Formaldehyde; see GI & CS Part 306.  
FormaldehydeF  
50-00-0  
0.75  
0.9  
2
2.5  
Formamide  
Formic acid  
Furfural  
75-12-7  
64-18-6  
98-01-1  
98-00-0  
20  
5
30  
9
30  
45  
x
x
2
8
Furfuryl alcohol  
10  
40  
15  
60  
Page 26  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Gasoline  
8006-61-9  
7782-65-2  
111-30-8  
300  
0.2  
900  
0.6  
500  
1500  
Germanium tetrahydride  
Glutaraldehyde  
0.2  
0.8  
Glycerin,  
Respirable mist  
Total mist  
56-81-5  
5
10  
Glycidol  
556-52-5  
25  
75  
Glycol monoethyl ether; see 2-Ethoxyethanol  
Grain dust (Oat, wheat, barley)  
Graphite, natural Respirable dust  
10  
7782-42-5  
2.5  
Graphite, synthetic,  
Respirable dust  
Total dust  
5
10  
GuthionR; see Azinphos methyl  
Gypsum,  
Respirable dust  
Total dust  
13397-24-5  
5
15  
Hafnium  
7440-58-6  
76-44-8  
0.5  
0.5  
x
Heptachlor  
Heptane (n-Heptane)  
142-82-5  
400  
1600  
500  
2000  
Page 27  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Hexachlorobutadiene  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
87-68-3  
77-47-4  
0.01  
1
0.02  
0.1  
10  
0.24  
x
x
x
Hexachlorocyclopentadiene  
Hexachloroethane  
Hexachloronaphthalene  
Hexafluoroacetone  
n-Hexane  
67-72-1  
1335-87-1  
684-16-2  
110-54-3  
0.2  
0.7  
180  
0.1  
50  
Varies with  
compound  
Hexane isomers  
500  
1800  
1000  
3600  
2-Hexanone (Methyl n-butyl ketone)  
Hexone (Methyl isobutyl ketone)  
sec-Hexyl acetate  
591-78-6  
108-10-1  
108-84-9  
107-41-5  
302-01-2  
61788-32-7  
10035-10-6  
7647-01-0  
74-90-8  
5
50  
50  
20  
205  
300  
75  
300  
x
x
Hexylene glycol  
25  
125  
Hydrazine  
0.1  
0.5  
0.1  
5
Hydrogenated terphenyls  
Hydrogen bromide  
3
10  
7
Hydrogen chloride  
5
Hydrogen cyanide  
4.7  
6
5
Hydrogen fluoride (as F)  
7664-39-3  
3
Page 28  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Hydrogen peroxide  
7722-84-1  
7783-07-5  
7783-06-4  
123-31-9  
999-61-1  
95-13-6  
1
0.05  
10  
1.4  
0.2  
14  
2
1
x
Hydrogen selenide (as Se)  
Hydrogen sulfide  
Hydroquinone  
15  
21  
2-Hydroxypropyl acrylate  
Indene  
0.5  
10  
3
45  
0.1  
Indium and compounds (as In)  
Iodine  
7440-74-6  
7553-56-2  
75-47-8  
0.1  
Iodoform  
0.6  
10  
10  
0.8  
Iron oxide fume  
1309-37-1  
13463-40-6  
Iron pentacarbonyl (as Fe)  
0.1  
0.2  
1.6  
Varies with  
compound  
Iron salts (soluble) (as Fe)  
1
Isoamyl acetate  
123-92-2  
123-51-3  
110-19-0  
78-83-1  
100  
100  
150  
50  
525  
360  
700  
150  
270  
125  
450  
x
Isoamyl alcohol (primary and secondary)  
Isobutyl acetate  
Isobutyl alcohol  
Isooctyl alcohol  
26952-21-6  
50  
Page 29  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Isophorone  
78-59-1  
4098-71-9  
109-59-1  
108-21-4  
67-63-0  
4
0.005  
25  
23  
0.02  
x
x
Isophorone diisocyanate (IPDI)  
2-Isopropoxyethanol  
Isopropyl acetate  
105  
950  
980  
12  
250  
400  
5
310  
500  
10  
1185  
1225  
24  
Isopropyl alcohol  
Isopropylamine  
75-31-0  
N-Isopropylaniline  
768-52-5  
108-20-3  
4016-14-2  
2
10  
Isopropyl ether  
500  
50  
2100  
240  
Isopropyl glycidyl ether (IGE)  
75  
360  
Kaolin,  
Respirable dust  
Total dust  
5
10  
Ketene  
463-51-4  
7439-92-1  
0.5  
0.9  
1.5  
3
Lead inorganic (as Pb); see GI Part 310. Lead in  
General IndustryF  
0.05  
(50 μg/m3)  
Limestone, (calcium carbonate)  
Respirable dust  
1317-65-3  
58-89-9  
5
15  
Total dust  
Lindane  
0.5  
x
Page 30  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Lithium hydride  
7580-67-8  
0.025  
1800  
L.P.G. (Liquified petroleum gas)  
68476-85-7  
1000  
Magnesite,  
Respirable dust  
Total dust  
546-93-0  
5
15  
Magnesium oxide fume, Total particulate  
Malathion dust  
1309-48-4  
121-75-5  
108-31-6  
1
10  
10  
x
Maleic anhydride  
Manganese,  
Compounds (as Mn)  
Fume (as Mn)  
7439-96-5  
1
3
5
Manganese cyclopentadienyl tricarbonyl (as Mn)  
Manganese tetroxide (as Mn)  
12079-65-1  
1317-35-7  
0.1  
1
x
Marble (calcium carbonate),  
Respirable dust  
1317-65-3  
5
15  
Total dust  
Mercury  
Inorganic and aryl compounds (As Hg)  
Organic compounds (as Hg)  
Vapor (as Hg)  
0.01  
0.05  
0.03  
0.1  
x
x
x
7439-97-6  
141-79-7  
Mesityl oxide  
15  
60  
25  
100  
Page 31  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
79-41-4  
ppmB  
20  
ppmB  
ppmB mg/m3C  
Methacrylic acid  
70  
x
Methanethiol; see Methyl mercaptan  
Methomyl (Lannate)  
16752-77-5  
72-43-5  
2.5  
10  
Methoxychlor dust  
2-Methoxyethanol; see Methyl cellosolve  
4-Methoxyphenol  
150-76-5  
79-20-9  
74-99-7  
5
250  
760  
x
x
x
Methyl acetate  
200  
1000  
1000  
10  
610  
1650  
1800  
35  
Methyl acetylene (Propyne)  
Methyl acetylene-propadiene mixture (MAPP)  
Methyl acrylate  
1250  
2250  
96-33-3  
126-98-7  
109-87-5  
67-56-1  
74-89-5  
Methylacrylonitrile  
1
3
Methylal (Dimethoxymethane)  
Methyl alcohol  
1000  
200  
10  
3100  
260  
12  
250  
325  
Methylamine  
Methyl amyl alcohol; see Methyl isobutyl carbinol  
Methyl n-amyl ketone  
110-43-0  
74-83-9  
100  
5
465  
20  
Methyl bromide  
x
Page 32  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Methyl n-butyl ketone; see 2-Hexanone  
Methyl cellosolve (2-Methoxyethanol)  
109-86-4  
110-49-6  
25  
25  
80  
x
x
Methyl cellosolve acetate (2-Methoxyethyl  
acetate)  
120  
Methyl chloride  
74-87-3  
71-55-6  
50  
350  
2
105  
1900  
8
100  
450  
4
210  
2450  
16  
x
Methyl chloroform (1,1,1-Trichloroethane)  
Methyl 2-cyanoacrylate  
Methylcyclohexane  
137-05-3  
108-87-2  
25639-42-3  
583-60-8  
400  
50  
1600  
235  
230  
Methylcyclohexanol  
o-Methylcyclohexanone  
50  
75  
345  
Methylcyclopentadienyl manganese tricarbonyl  
(as Mn)  
12108-13-3  
0.2  
x
Methyl demeton  
8022-00-2  
101-14-4  
5124-30-1  
101-68-8  
0.02  
0.5  
0.22  
x
x
4,4'-Methylene bis(2-chloroaniline) (MBOCA)  
Methylene bis(4-cyclohexylisocyanate) (MCBI)  
Methylene bisphenyl isocyanate (MDI)  
0.01  
0.02  
0.11  
0.2  
Methylene chloride, see OH Part 313. Methylene  
ChlorideF  
75-09-2  
25  
87  
125  
434  
Page 33  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
101-77-9  
ppmB  
ppmB  
ppmB mg/m3C  
Methylenedianiline (MDA); see GI Part 303.  
Methylenedianiline (MDA) in General  
IndustryF  
10  
ppb**  
100  
ppb**  
0.08 mg/m3  
0.8 mg/m3  
Methyl ethyl ketone (MEK); see 2-Butanone  
Methyl ethyl ketone peroxide (MEKP)  
Methyl formate  
1338-23-4  
107-31-3  
60-34-4  
100  
150  
375  
0.7  
5
x
x
x
250  
Methyl hydrazine  
0.2  
0.35  
Methyl iodide  
74-88-4  
2
10  
Methyl isoamyl ketone  
Methyl isobutyl carbinol  
Methyl isobutyl ketone; see Hexone  
Methyl isocyanate (MIC)  
Methyl isopropyl ketone  
Methyl mercaptan  
110-12-3  
108-11-2  
50  
25  
240  
100  
40  
165  
624-83-9  
563-80-4  
74-93-1  
80-62-6  
298-00-0  
0.02  
200  
0.5  
100  
0.05  
705  
1
x
Methyl methacrylate  
410  
0.2  
Methyl parathion  
x
Methyl propyl ketone; see 2-Pentanone  
Methyl silicate  
681-84-5  
1
6
5
30  
Page 34  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
alpha-Methyl styrene  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
98-83-9  
50  
240  
5
100  
485  
Metribuzin  
21087-64-9  
Mica; see Silicates  
Molybdenum, (as Mo)  
Insoluble compounds  
Soluble compounds  
7439-98-7  
10  
5
Monocrotophos (AzodrinR)  
Monomethyl aniline  
Morpholine  
6923-22-4  
100-61-8  
110-91-8  
8030-30-6  
91-20-3  
0.25  
2
x
x
0.5  
20  
70  
30  
105  
Naphtha (Coal tar)  
Naphthalene  
100  
10  
400  
50  
15  
75  
alpha-Naphthylamine; see GI Part 350.  
CarcinogensF  
beta-Naphthylamine; see GI Part 350.  
CarcinogensF  
134-32-7  
91-59-8  
Nickel carbonyl (as Ni)  
13463-39-3 0.001  
0.007  
Nickel,  
Metal and insoluble compounds (as Ni)  
Soluble compounds (as Ni)  
7440-02-0  
54-11-5  
1
0.1  
Nicotine  
0.5  
x
Page 35  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Nitric acid  
7697-37-2  
10102-43-9  
100-01-6  
98-95-3  
2
25  
5
30  
3
4
10  
x
x
x
Nitric oxide  
p-Nitroaniline  
Nitrobenzene  
1
5
p-Nitrochlorobenzene  
100-00-5  
1
4-Nitrodiphenyl; see GI Part 350. CarcinogensF  
92-93-3  
Nitroethane  
79-24-3  
10102-44-0  
7783-54-2  
55-63-0  
100  
310  
1
1.8  
x
Nitrogen dioxide  
Nitrogen trifluoride  
Nitroglycerin  
10  
29  
0.1  
Nitromethane  
75-52-5  
100  
25  
10  
250  
90  
35  
1-Nitropropane  
2-Nitropropane  
108-03-2  
79-46-9  
N-Nitrosodimethylamine; see GI Part 350.  
CarcinogensF  
62-75-9  
99-08-1  
Nitrotoluene (o-,m-,p-isomers)  
2
11  
x
Nitrotrichloromethane; see Chloropicrin  
Page 36  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Nonane  
111-84-2  
2234-13-1  
111-65-9  
200  
1050  
0.1  
1450  
5
0.3  
1800  
x
Octachloronaphthalene  
Octane  
300  
375  
Oil mist, mineral  
Osmium tetroxide (as Os)  
Oxalic acid  
8012-95-1  
20816-12-0  
144-62-7  
0.002  
1
0.006  
2
Oxygen difluoride  
Ozone  
7783-41-7  
10028-15-6  
8002-74-2  
0.05  
0.1  
0.1  
0.2  
2
0.3  
0.6  
Paraffin wax fume  
1910-42-5  
2074-50-2  
4685-14-7  
Paraquat, respirable dust  
Parathion  
0.1  
0.1  
x
x
56-38-2  
Particulates not otherwise regulated,  
Respirable dust  
5
15  
Total dust  
Pentaborane  
19624-22-7 0.005  
0.01  
0.5  
0.015  
0.03  
x
x
Pentachloronaphthalene  
Pentachlorophenol  
1321-64-8  
87-86-5  
0.5  
Page 37  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
115-77-5  
ppmB  
ppmB  
ppmB mg/m3C  
Pentaerythritol,  
Respirable dust  
Total dust  
5
10  
Pentane  
109-66-0  
107-87-9  
127-18-4  
594-42-3  
7616-94-6  
600  
200  
25  
1800  
700  
170  
0.8  
750  
250  
2250  
875  
2-Pentanone (Methyl propyl ketone)  
Perchloroethylene (Tetrachloroethylene)  
Perchloromethyl mercaptan  
0.1  
3
Perchloryl fluoride  
14  
6
28  
Perlite  
Respirable dust  
Total dust  
93763-70-3  
5
15  
Petroleum distillates (Naphtha) (Rubber solvent)  
Phenol  
400  
5
1600  
19  
5
x
x
x
108-95-2  
92-84-2  
106-50-3  
101-84-8  
Phenothiazine  
p-Phenylenediamine  
0.1  
7
Phenyl ether, vapor  
1
Phenyl ether-biphenyl mixture, vapor  
Phenylethylene; see Styrene  
Phenyl glycidyl ether (PGE)  
1
7
122-60-1  
1
6
Page 38  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Phenylhydrazine  
Phenyl mercaptan  
Phenylphosphine  
Phorate  
100-63-0  
108-98-5  
638-21-1  
298-02-2  
7786-34-7  
75-44-5  
5
0.5  
20  
2
10  
45  
x
x
x
0.05  
0.25  
0.05  
0.1  
0.4  
0.4  
1
0.2  
0.3  
Phosdrin (MevinphosR)  
Phosgene (Carbonyl chloride)  
Phosphine  
0.1  
0.3  
7803-51-2  
7664-38-2  
7723-14-0  
10025-87-3  
10026-13-8  
1314-80-3  
7719-12-2  
85-44-9  
1
1
Phosphoric acid  
3
Phosphorus (yellow)  
Phosphorus oxychloride  
Phosphorus pentachloride  
Phosphorus pentasulfide  
Phosphorus trichloride  
Phthalic anhydride  
0.1  
0.6  
1
0.1  
1
3
0.2  
1
1.5  
6
0.5  
3
m-Phthalodinitrile  
626-17-5  
5
Picloram,  
Respirable dust  
Total dust  
1918-02-1  
5
10  
Page 39  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Picric acid  
88-89-1  
142-64-3  
83-26-1  
0.1  
5
x
Piperazine dihydrochloride  
Pindone (2-Pivalyl-1,3-indandione)  
0.1  
Plaster of Paris (Calcium sulfate),  
Respirable dust  
26499-65-0  
7440-06-4  
65997-15-1  
5
15  
Total dust  
Platinum (as Pt)  
Metal  
1
Soluble salts  
0.002  
Portland cement,  
Respirable dust  
Total dust  
5
10  
Potassium hydroxide  
Propane  
1310-58-3  
74-98-6  
1000  
1
1800  
2
2
x
Propargyl alcohol  
107-19-7  
beta-Propriolactone; see GI Part 350. CarcinogensF  
57-57-8  
Propionic acid  
79-09-4  
114-26-1  
109-60-4  
71-23-8  
10  
30  
0.5  
840  
500  
Propoxur (Baygon)  
n-Propyl acetate  
n-Propyl alcohol  
200  
200  
250  
250  
1050  
625  
Page 40  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
n-Propyl nitrate  
627-13-4  
78-87-5  
25  
75  
105  
350  
0.3  
360  
5
40  
110  
170  
510  
x
Propylene dichloride  
Propylene glycol dinitrate  
Propylene glycol monomethyl ether  
Propylene imine  
6423-43-4  
107-98-2  
75-55-8  
0.05  
100  
2
150  
540  
Propylene oxide  
75-56-9  
20  
50  
Propyne; see Methyl acetylene  
Pyrethrum  
8003-34-7  
110-86-1  
106-51-4  
108-46-3  
5
5
Pyridine  
15  
0.4  
45  
Quinone  
0.1  
10  
Resorcinol  
20  
90  
Rhodium,  
Insoluble compounds (as Rh)  
Metal fume (as Rh)  
Soluble compounds (as Rh)  
0.1  
0.1  
0.001  
7440-16-6  
Ronnel  
299-84-3  
10  
0.1  
5
Rosin core solder pyrolysis products, as  
formaldehyde  
Rotenone  
83-79-4  
Page 41  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Rouge,  
Respirable dust  
Total dust  
5
10  
Selenium compounds (as Se)  
7782-49-2  
7783-79-1  
0.05  
0.2  
0.4  
6
Selenium hexafluoride (as Se)  
Silica, amorphous, precipitated and gel  
112926-00-8  
Silica, amorphous, diatomaceous earth, containing  
less than 1% crystalline silica  
61790-53-2  
6
Silica, crystalline, respirable dust  
Cristobalite  
See GI Part 590. Silica in General Industry  
14464-46-1  
14808-60-7  
15468-32-3  
1317-95-9  
60676-86-0  
0.05  
0.05  
0.05  
0.05  
0.1  
Quartz  
Tridymite  
Tripoli (as quartz)  
Silica, fused, Respirable dust  
Page 42  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Silicates (less than 1% crystalline silica)  
Mica, respirable dust  
12001-26-2  
3
3
6
Soapstone, respirable dust  
Soapstone, total dust  
Talc (containing asbestos); use asbestos limit  
Talc (containing no asbestos), respirable dust  
Tremolite  
OH Part 305 “Asbestos for General Industry,”  
14807-96-6  
2
OH Part 305 “Asbestos for General Industry,”  
Silicon,  
Respirable dust  
Total dust  
7440-21-3  
409-21-2  
5
10  
Silicon carbide,  
Respirable dust  
Total dust  
5
10  
Silicon tetrahydride  
7803-62-5  
7440-22-4  
5
7
Silver, metal and soluble compounds (as Ag)  
Soapstone; see Silicates  
0.01  
Sodium azide  
(as HN3)  
26628-22-8  
7631-90-5  
0.1  
0.3  
x
x
(as NaN3)  
Sodium bisulfite  
5
Page 43  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
Sodium fluoroacetate  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
62-74-8  
1310-73-2  
7681-57-4  
0.05  
0.15  
2
x
Sodium hydroxide  
Sodium metabisulfite  
5
Starch,  
Respirable dust  
Total dust  
9005-25-8  
5
15  
Stibine  
7803-52-3  
8052-41-3  
57-24-9  
0.1  
100  
0.5  
525  
0.15  
215  
Stoddard solvent  
Strychnine  
Styrene  
100-42-5  
50  
100  
425  
0.00006  
(60 min.)  
Subtilisins (Proteolytic enzymes)  
9014-01-1  
57-50-1  
Sucrose,  
Respirable dust  
Total dust  
5
15  
Sulfur dioxide  
7446-09-5  
2551-62-4  
7664-93-9  
10025-67-9  
5714-22-7  
2
1000  
5
6000  
1
5
10  
Sulfur hexafluoride  
Sulfuric acid  
Sulfur monochloride  
Sulfur pentafluoride  
1
6
0.01  
0.1  
Page 44  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Sulfur tetrafluoride  
Sulfuryl fluoride  
Sulprofos  
7783-60-0  
2699-79-8  
35400-43-2  
5
20  
1
10  
40  
0.1  
0.4  
SystoxR; see Demeton  
2,4,5-T (2,4,5-trichlorophenoxyacetic acid)  
Talc; see Silicates  
93-76-5  
10  
Tantalum, metal and oxide dust  
TEDP (Sulfotep)  
7440-25-7  
3689-24-5  
13494-80-9  
7783-80-4  
5
x
0.2  
0.1  
0.2  
Tellurium and compounds (as Te)  
Tellurium hexafluoride (as Te)  
0.02  
Temephos,  
Respirable dust  
Total dust  
3383-96-8  
5
10  
TEPP  
107-49-3  
26140-60-3  
76-11-9  
0.05  
0.5  
5
x
x
Terphenyls  
1,1,1,2-Tetrachloro-2, 2-difluoroethane  
1,1,2,2-Tetrachloro-1, 2-difluoroethane  
1,1,2,2-Tetrachloroethane  
500  
500  
1
4170  
4170  
7
76-12-0  
79-34-5  
Page 45  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Tetrachloroethylene; see Perchloroethylene  
Tetrachloromethane; see Carbon tetrachloride  
Tetrachloronaphthalene  
1335-88-2  
78-00-2  
2
0.075  
590  
0.075  
3
x
x
x
x
x
x
Tetraethyl lead (as Pb)  
Tetrahydrofuran  
109-99-9  
75-74-1  
200  
250  
735  
Tetramethyl lead (as Pb)  
Tetramethyl succinonitrile  
3333-52-6  
509-14-8  
7722-88-5  
479-45-8  
7440-28-0  
0.5  
1
Tetranitromethane  
8
Tetrasodium pyrophosphate  
Tetryl (2,4,6-Trinitrophenylmethylnitramine)  
Thallium, soluble compounds (as Tl)  
5
1.5  
0.1  
4,4'-Thiobis(6-tert-butyl-m-cresol)  
Respirable dust  
96-69-5  
5
10  
Total dust  
Thioglycolic acid  
Thionyl chloride  
Thiram  
68-11-1  
7719-09-7  
137-26-8  
1
4
5
1
5
x
Page 46  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Tin, Inorganic compounds (except oxides)  
(as Sn)  
7440-31-5  
7440-31-5  
21651-19-4  
2
0.1  
2
x
Organic compounds (as Sn)  
Oxides (as Sn)  
Titanium dioxide Total dust  
Toluene  
13463-67-7  
108-88-3  
584-84-9  
108-44-1  
95-53-4  
100  
0.005  
2
10  
375  
0.04  
9
150  
0.02  
560  
0.15  
x
x
x
Toluene-2,4-diisocyanate (TDI)  
m-Toluidine  
o-Toluidine  
5
22  
p-Toluidine  
106-49-0  
2
9
Toxaphene; see Chlorinated camphene  
Tremolite; see Silicates  
Tributyl phosphate  
126-73-8  
76-03-9  
0.2  
1
2.5  
7
5
Trichloroacetic acid  
1,2,4-Trichlorobenzene  
1,1,1-Trichloroethane; see Methyl chloroform  
1,1,2-Trichloroethane  
Trichloroethylene  
120-82-1  
40  
79-00-5  
79-01-6  
10  
50  
45  
x
270  
200  
1080  
Page 47  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Trichloromethane; see Chloroform  
Trichloronaphthalene  
1321-65-9  
96-18-4  
10  
5
x
1,2,3-Trichloropropane  
1,1,2-Trichloro-1,2,2-trifluoroethane  
Triethylamine  
60  
76-13-1  
1000  
10  
7600  
40  
1250  
15  
9500  
60  
121-44-8  
75-63-8  
Trifluorobromomethane  
Trimellitic anhydride  
1000  
0.005  
10  
6100  
0.04  
24  
552-30-7  
75-50-3  
Trimethylamine  
15  
36  
Trimethyl benzene  
25551-13-7  
121-45-9  
25  
125  
10  
Trimethyl phosphite  
2
2,4,6-Trinitrophenol; see Picric acid  
2,4,6-Trinitrophenylmethylnitramine; see Tetryl  
2,4,6-Trinitrotoluene (TNT)  
Triorthocresyl phosphate  
Triphenyl amine  
118-96-7  
78-30-8  
0.5  
0.1  
5
x
x
603-34-9  
115-86-6  
Triphenyl phosphate  
3
Page 48  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Tungsten  
Insoluble compounds (as W)  
Soluble compounds (as W)  
7440-33-7  
8006-64-2  
7440-61-1  
110-62-3  
5
1
10  
3
Turpentine  
100  
560  
Uranium (as U)  
Insoluble compounds  
Soluble compounds  
0.2  
0.05  
0.6  
-
n-Valeraldehyde  
50  
175  
Vanadium pentoxide  
Fume (as V2O5)  
1314-62-1  
0.05  
0.05  
Respirable dust (as V2O5)  
Vegetable oil mists  
Respirable mist  
Total mist  
5
15  
Vinyl acetate  
108-05-4  
10  
30  
20  
60  
Vinyl benzene; see Styrene  
Vinyl bromide  
593-60-2  
75-01-4  
5
1
20  
Vinyl chloride; see GI Part 302. Vinyl ChlorideF  
2.5  
5
12.8  
Vinyl cyanide; see Acrylonitrile  
Vinyl cyclohexene dioxide  
106-87-6  
75-35-4  
10  
1
60  
4
x
Vinylidene chloride (1,1-Dichloroethylene)  
Page 49  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Vinyl toluene  
VM & P Naphtha  
Warfarin  
25013-15-4  
8032-32-4  
81-81-2  
100  
300  
480  
1350  
0.1  
5
400  
1800  
Welding fumes (Total particulate)*  
Wood dust, all soft and hard woods (except  
Western red cedar)  
5
10  
Wood dust, Western red cedar  
Xylene (o-,m-,p-isomers) (Dimethyl benzene)  
m-Xylene-alpha, alpha’-diamine  
Xylidine  
100  
2.5  
435  
150  
655  
x
x
1330-20-7  
1477-55-0  
1300-73-8  
7440-65-5  
7646-85-7  
0.1  
2
10  
1
Yttrium  
Zinc chloride fume  
1
2
0.005  
Zinc chromates (as Cr+6); see OH Part 315.  
Chromium (VI) in General IndustryF,G  
Varies with  
compound  
(5 μg/m3)  
Zinc oxide fume  
1314-13-2  
1314-13-2  
5
10  
Zinc oxide,  
Respirable dust  
Total dust  
5
10  
Page 50  
TABLE G-1-A. EXPOSURE LIMITS FOR AIR CONTAMINANTS  
TWA  
STELD  
mg/m3C mg/m3C  
Ceiling  
Skin  
Designation  
Substance  
CAS No.A  
ppmB  
ppmB  
ppmB mg/m3C  
Zinc stearate  
Respirable dust  
Total dust  
557-05-1  
5
10  
Zirconium compounds (as Zr)  
7440-67-7  
5
10  
All MIOSHA Standards shown in this table are referenced in R 325.51101.  
As determined from breathing-zone air samples.  
** Parts per billion.  
*
The CAS number is for information only. Enforcement is based on the substance name. For an entry covering more than 1 metal compound  
measured as the metal, the CAS number for the metal is given - not the CAS number for the individual compounds.  
A
B
C
D
Parts of vapor or gas per million parts of contaminated air by volume at 25 °C and 760 Torr.  
Approximate milligrams of substance per cubic meter of air.  
Duration is for 15 minutes, unless otherwise noted.  
The GI & CS Part 311. Benzenestandard applies to all occupational exposures to benzene, except some sub-segments of industry where  
exposures are consistently under the action level. These sub-segments include the distribution and sale of fuels, sealed containers and  
pipelines, coke production, oil and gas drilling and production, natural gas processing, and the percentage exclusion for liquid mixtures. For  
the excepted sub-segments, the benzene limits in table G-2 apply.  
E
F
Caution--this rule contains extensive requirements for exposure to these substances.  
If the exposure limit in OH Part 315. Chromium (VI) in General Industryis stayed or is otherwise not in effect, the exposure limit is a  
G
ceiling of 0.1 mg/m3.  
Page 51  
TABLE G-2. EXPOSURE LIMITS FOR AIR CONTAMINATES  
Acceptable maximum peak above the acceptable  
ceiling concentration for an 8-hour workshift.  
8-hour, time-weighted  
average  
Acceptable ceiling  
concentration  
Substance  
Concentration  
Maximum duration  
S
S
BenzeneE,F  
Ethylene dibromide  
10 ppm  
20 ppm  
25 ppm  
30 ppm  
50 ppm  
50 ppm  
10 minutes  
5 minutes  
Note: S above signifies that skin contact shall not be allowed.  
The GI & CS Part 311. Benzenestandard applies to all occupational exposures to benzene, except some sub-segments of industry where  
exposures are consistently under the action level. These sub-segments include the distribution and sale of fuels, sealed containers and  
pipelines, coke production, oil and gas drilling and production, natural gas processing, and the percentage exclusion for liquid mixtures. For  
the excepted sub-segments, the benzene limits in this table apply.  
E
F
Caution--this rule contains extensive requirements for exposure to these substances.  
History: 1990 AACS; 2001 AACS; 2013 AACS; 2017 AACS; 2019 AACS.  
Page 52  
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