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Table Z-1 Limits for Air Contaminants

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Table Z-1 Limits for Air Contaminants
Table of Contents

Table Z-1 - Page 1
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Substance CAS No.
(d)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Acetaldehyde

75-07-0

100

180

150

270

 

 

 

 

Acetic acid

64-19-7

10

25

 

 

 

 

 

 

Acetic anhydride

108-24-7

 

 

 

 

5

20

 

 

Acetone

67-64-1

750

1800

1000

2400

 

 

 

 

Acetonitrile

75-05-8

40

70

60

105

 

 

 

 

2-Acetylaminofluorene; see 1910.1014

53-96-3

 

 

 

 

 

 

 

 

Acetylene dichloride; see 1, 2-Dichloroethylene

 

 

 

 

 

 

 

 

 

Acetylene tetrabromide

79-27-6

1

14

 

 

 

 

 

 

Acrolein

107-02-8

0.1

0.25

0.3

0.8

 

 

 

 

Acrylamide

79-06-1

 

0.03

 

 

 

 

X

 

Acrylonitrile; see 1910.1045

107-13-1

 

 

 

 

 

 

 

 

Aldrin

309-00-2

 

0.25

 

 

 

 

X

 

Allyl alcohol

107-18-6

2

5

4

10

 

 

X

 

Allyl chloride

107-05-1

1

3

2

6

 

 

 

 

Allyl glycidyl ether (AGE)

106-92-3

5

22 10 44  

 

 

 

Allyl propyl disulfide

2179-59-1

2

12

3

18

 

 

 

 

alpha Alumina
  Total dust
  Respirable fraction

1344-28-1

 

 
  10
  5

 

 

 

 

 

 

Aluminum (as A1) Metal
  Total dust
  Respirable fraction
 Pyro powders
 Welding fumes*
 Soluble salts
 Alkyls

7429-90-5

 

 
  15
  5
  5
  5
  2
  2

 

 

 

 

 

 

4-Aminodiphenyl; see 1910.1011

92-67-1

 

 

 

 

 

 

 

 

2-Aminoethanol; see Ethanolamine

 

 

 

 

 

 

 

 

 

2-Aminopyridine

504-29-0

0.5

2

 

 

 

 

 

 

Amitrole

61-82-5

 

0.2

 

 

 

 

 

 

Ammonia

7664-41-7

 

 

35

27

 

 

 

 

Ammonium sulfamate
  Total dust
  Respirable fraction

7773-06-0

 

 
  10
  5

 

 

 

 

 

 

n-Amyl acetate

628-63-7

100

525

 

 

 

 

 

 

sec-Amyl acetate

626-38-0

125

650

 

 

 

 

 

 

Aniline and homologs

62-53-3

2

8

 

 

 

 

X

 

Anisidine (o-,p-isomers)

29191-52-4

 

0.5

 

 

 

 

X

 

Antimony and compounds (as Sb)

7440-36-0

 

0.5

 

 

 

 

 

 

ANTU (alpha Naphthyl-thiourea)

86-88-4

 

0.3

 

 

 

 

 

table of contents

Table Z-1 - Page 2
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Arsenic, inorganic compounds (as As); see 1910.1018 7440-38-2              

 

Arsenic, organic compounds (as As) 7440-38-2   0.5          

 

Arsine 7784-42-1 0.05 0.2          

 

Asbestos; see 1910.1001 and 1926.1101 varies              

 

Atrazine 1912-24-9 5            

 

Azinphos-methyl 86-50-0   0.2         X

 

Barium, soluble compounds (as Ba) 7440-39-3   0.5          

 

Barium sulfate
  Total dust
  Respirable fraction
7727-43-7  
 
  10
  5
         

 

Benomyl
  Total dust
  Respirable fraction
17804-35-2  
 
  10
  5
         

 

Benzene; see 1910.1028
  See Table Z-2 for the limits applicable in the Operations or sectors excluded in 1910.1028*
71-43-2              

 

Benzidine; see 1910.1010 92-87-5              

 

p-Benzoquinone; see Quinone                

 

Benzo (a) pyrene; see Coal Ta pitch volatiles                

 

Benzoyl peroxide 94-36-0   5          

 

Benzyl chloride 100-44-7 1 5          

 

Beryllium and beryllium compounds (as Be) 7440-41-7   Table Z-2   Table Z-2   Table Z-2  

 

Biphenyl; see Diphenyl                

 

Bismuth telluride, Undoped
  Total dust
  Respirable fraction
1304-82-1  
 
  15
  5
         

 

Bismuth telluride, Se-doped     5          

 

Borates, tetra, sodium salts
  Anhydrous
  Decahydrate
  Pentahydrate
 
  1330-43-4
  1303-96-4
  12179-04-3
 
 
  10
  10
  10
         

 

Boron oxide
  Total dust
1303-86-2  
 
  10
         

 

Boron tribromide 10294-33-4         1 10  

 

Boron trifluoride 7637-07-2         1 3  

 

Bromacil 314-40-9 1 10          

 

Bromine 7726-95-6 0.1 0.7 0.3 2      

 

Bromine pentafluoride 7789-30-2 0.1 0.7          

 

Bromoform 75-25-2 0.5 5         X

 

Butadiene (1, 3-Butadiene) 106-99-0 1000 2200          

 

Butane 106-97-8 800 1900          

table of contents

Table Z-1 - Page 3
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Butanethiol; see Butyl mercaptan                

 

2-Butanone (Methyl ethyl ketone) 78-93-3 200 590 300 885      

 

2-Butoxyethanol 111-76-2 25 120         X

 

n-Butyl-acetate 123-86-4 150 710 200 950      

 

sec-Butyl acetate 105-46-4 200 950          

 

tert-Butyl-acetate 540-88-5 200 950          

 

Butyl acrylate 141-32-2 10 55          

 

n-Butyl alcohol 71-36-3         50 150 X

 

sec-Butyl alcohol 78-92-2 100 305          

 

tert-Butyl alcohol 75-65-0 100 300 150 450      

 

Butylamine 109-73-9         5 15 X

 

tert-Butyl chromate (as CrO3) 1189-85-1           0.1 X

 

n-Butyl glycidyl ether (BGE) 2426-08-6 25 135          

 

n-Butyl lactate 138-22-7 5 25          

 

Butyl mercaptan 109-79-5 0.5 1.5          

 

o-sec-Butylphenol 89-72-5 5 30         X

 

p-tert-Butyltoluene 98-51-1 10 60 20 120      

 

Cadmium fume (as Cd) 7440-43-9   0.1       0.3  

 

Cadmium dust (as Cd) 7440-43-9   0.2       0.6  

 

Calcium Carbonate
  Total dust
  Respirable fraction
1317-65-3  
 
  15
  5
         

 

Calcium cyanamide 156-62-7   0.5          

 

Calcium hydroxide 1305-62-0   5          

 

Calcium oxide 1305-78-8   5          

 

Calcium silicate
  Total dust
  Respirable fraction
1344-95-2  
 
  15
  5
         

 

Calcium sulfate
  Total dust
  Respirable fraction
7778-18-9  
 
  15
  5
         

 

Camphor, synthetic 76-22-2   2          

 

Caprolactam
  Dust
  Vapor
105-60-2
 
   
  5
 
  1
  20
 
   
  10
 
  3
  40
     

 

Captafol (DifolatanR) 2425-06-1   0.1          

 

Captan 133-06-2   5          

 

Carbaryl ((SevinR) 63-25-2   5          

 

Carbofuran (FuradanR) 1563-66-2   0.1          

 

Carbon black 1333-86-4   3.5          

 

Carbon dioxide 124-38-9 10000f 18000 30000 54000      

 

Carbon disulfide 75-15-0 4 12 12 36      

table of contents

Table Z-1 - Page 4 
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Carbon monoxide 630-08-0 35 40     200 229  

 

Carbon tetrabromide 558-13-4 0.1 1.4 0.3 4      

 

Carbon tetrachloride 56-23-5 2 12.6          

 

Carbonyl fluoride 353-50-4 2 5 5 15      

 

Catechol (pyrocatechol) 120-80-9 5 20          

 

Cellulose
  Total dust
  Respirable fraction
9004-34-6  
 
  15
  5
         

 

Cesium hydroxide 21351-79-1   2          

 

Chlordane 57-74-9   0.5         X

 

Chlorinated camphene 8001-35-2   0.5   1     X

 

Chlorinated diphenyl oxide 55720-99-5   0.5          

 

Chlorine 7782-50-5 0.5 1.5 1 3      

 

Chlorine dioxide 10049-04-4 0.1 0.3 0.3 0.9      

 

Chlorine trifluoride 7790-91-2         0.1 0.4  

 

Chloroacetaldehyde 107-20-0         1 3  

 

a-Chloroacetophene (Phenacyl chloride) 532-27-4 0.05 .03          

 

Chloroacetyl chloride 79-04-9 0.05 0.2          

 

Chlorobenzyne 108-90-7 75 350          

 

o-Chlorobenzylidene malononitrile 2698-41-1         0.05 0.4 X

 

Chlorobromomethane 74-97-5 200 1050          

 

2-Chloro-1, 3-butadiene; see b-Chloropene                

 

Chlorodifluoromethane 75-45-6 1000 3500          

 

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 2 9.78          

 

bis (Chloromethyl) ether; see 1910.1008 542-88-1              

 

Chlotromethyl methyl ether; see 1910.1006 107-30-2              

 

1-Chloro-1-nitropropane 600-25-9 2 10          

 

Chloropentafluoroethane 76-15-3 1000 6320          

 

Chloropicrine 76-06-2 0.1 0.7          

 

beta-Chloroprene 126-99-8 10 35          

 

o-Chlorostyrene 2039-87-4 50 285 75 428      

 

0-Chlorotoluene 95-49-8 50 250          

 

2-Chloro-6-trichloro-methyl pyridine
  Total dust
  Respirable fraction
1929-82-4  
 
  15
  5
         

 

Chlorpyrifos 2921-88-2 0.2           X

 

Chromic acid and chromates (as CrO3) 7440-47-3         0.1    

table of contents

Table Z-1 - Page 5
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Chromium (II) compounds (as Cr) 7440-47-3   0.5          

 

Chromium (III) compounds (as Cr) 7440-47-3   0.5          

 

Chromium metal (as Cr) 7440-47-3   1          

 

Chrysene; see Coal tar pitch volatiles                

 

Clopidol
  Total dust
  Respirable fraction
2971-90-6  
 
  15
  5
         

 

Coal dust (less than 5% SiO2), Respirable fraction     2          

 

Coal dust (greater than or equal to 5% SiO2), Respirable quartz fraction     0.1          

 

Coal tar pitch volatiles (benzene fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene. 65996-93-2   0.2          

 

Cobalt metal, dust, and fume (as Co) 7440-48-4   0.05          

 

Cobalt carbonyl (as Co) 10210-68-1   0.1          

 

Cobalt hydrocarbonyl (as Co) 16842-03-8   0.1          

 

Coke oven emissions; see 1910.1029                

 

Copper
  Fume (as Cu)
  Dusts and mists (as Cu)
7440-50-8  
 
  0.1
  1
         

 

Cotton dust (raw)     1          

 

This 8-hour TWA applies to respirable dust as measured by a vertical elutriator cotton dust sampler or equivalent instrument. The time-weighted average applies to the cotton waste processing operations of waste recycling (sorting, blending, cleaning and willowing) and garneting. See also 1910.1043 for cotton dust limits applicable to other sectors.

 

Crag herbicide (Sesone)
  Total dust
  Respirable fraction
   
 
  10
  5
         

 

Cresol, all isomers 1319-77-3 5 22         X

 

Crotonaldehyde 123-73-9;
4170-30-3
2 6          

 

Crufomate 299-86-5   5          

 

Cumene 98-82-8 50 245         X

 

Cyanamide 420-04-2   2          

 

Cyanides (as CN) varies with compound   5          

 

Cyanogen 460-19-5 10 20          

 

Cyanogen chloride 506-77-4         0.3 0.6  

 

Cyclohexane 110-82-7 300 1050          

 

Cyclohexanol 108-93-0 50 200         X

 

Cyclohexanone 108-94-1 25 100         X

 

Cyclohexene 110-83-8 300 1015          

table of contents

Table Z-1 - Page 6 
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Cyclohexylamine 108-91-8 10 40          

 

Cyclonite 121-82-4   1.5         X

 

Cyclopentadiene 542-92-7 75 200          

 

Cyclopentane 287-92-3 600 1720          

 

Cyhexatin 13121-70-5   5          

 

2,4-D (Dichlorophenoxyacetic acid) 94-75-7   10          

 

Decaborane 17702-41-9 0.05 .3 0.15 0.9     X

 

Demeton (SystoxR) 8065-48-3   0.1         X

 

Dichlorodiphenyltrichloroethane (DDT) 50-29-3   1         X

 

Dichlorvos (DDVP) 62-73-7   1         X

 

Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone) 123-42-2 50 240          

 

1,2-Diaminoethane; see Ethylenediamine                

 

Diazinon 333-41-5   0.1         X

 

Diazomethane 334-88-3 0.2 0.4          

 

Diborane 19287-45-7 0.1 0.1          

 

1,2-Dibromo-3-chloropropane (DBCP); see 1910.1044 96-12-8              

 

2-N-Dibutyleaminoethanol 102-81-8 2 14          

 

Dibutyl phosphate 107-66-4 1 5 2 10      

 

Dibutyl phthalate 84-74-2   5          

 

Dichloroacetylene 7572-29-4         0.1 0.4  

 

o-Dichlorobenzene 95-50-1         50 300  

 

p-Dichlorobenzene 106-46-7 75 450 110 675      

 

3,3'-Dichlorobenzidine; see 1910.1007 91-94-1              

 

Dichlorodifluoromethane 75-71-8 1000 4950          

 

1,3-Dichloro-5,5-dimethyl hydantoin 118-52-5   0.2   0.4      

 

1,1-Dichloroethane 75-34-3 100 400          

 

1,2-Dichloroethylene 540-59-0 200 790          

 

Dichloroethyl ether 111-44-4 5 30 10 60     X

 

Dichloromethane; see Methylene chloride                

 

Dichloromonofluoromethane 75-43-4 10 40          

 

1,1-Dichloro-1-nitroethane 594-72-9 2 10          

 

1,2-Dichloropropane; see Propylene dichloride                

 

1,3-Dichloropropane 542-75-6 1 5          

 

2,2-Dichloropropionic acid 75-99-0 1 6          

 

Dichlorotetrafluoroethane 76-14-2 1000 7000          

 

Dicrotophos 141-66-2   0.25         X

 

Dicyclopentadiene 77-73-6 5 30          

 

Dicyclopentadienyl iron
  Total dust
  Respirable fraction
102-54-5  
 
  10
  5
         

 

Dieldrin 60-57-1   0.25         X

 

Diethanolamine 111-42-2 3 15          

table of contents

Table Z-1 - Page 7 
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Diethylamine 109-89-7 10 30 25 75      

 

2-Diethylaminoethanol 100-37-8 10 50         X

 

Diethylene triamine 111-40-0 1 4          

 

Diethyl ether; see Ethyl ether                

 

Diethyl ketone 96-22-0 200 705          

 

Diethyl phthalate 84-66-2   5          

 

Difluorodibromomethane 75-61-6 100 860          

 

Diglycidyl ether (DGE) 2238-07-5 0.1 0.5          

 

Dihydroxybenzene; see Hydroquinone                

 

Diisobutyl ketone 108-83-8 25 150          

 

Diisopropylamine 108-18-9 5 20         X

 

4-Dimethylaminoazobenzene; see 1910.1015 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-Dimethylaniline) 121-69-7 5 25 10 50     X

 

Dimethylbenzene; see Xylene                

 

Dimethyl-1,2-dibromo-2,2-dichloroethyl phosphate 300-76-5   3         X

 

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 77-78-1 0.1 0.5         X

 

Dinitolmide (3,5-Dinitro-o-toluamide) 148-01-6   5          

 

Dinitrobenzene (all isomers)
  alpha
  meta
  para
 
  528-29-0
  99-65-0
  100-25-4
 
 
  1
  1
  1
       
 
  X
  X
  X

 

Dinitro-o-cresol 534-52-1   0.2         X

 

Dinitrotoluene 25321-14-6   1.5         X

 

Dioxane (Diethylene dioxide) 123-91-1 25 90         X

 

Dioxathion (Delnav) 78-34-2   0.2         X

 

Diphenyl (Biphenyl) 92-52-4 0.2 1          

 

Diphenylamine 122-39-4   10          

 

Diphenylmethane diisocyanate; see Methylene bisphenylisocyanate                

 

Dipropylene glycol methyl ether 34590-94-8 100 600 150 900     X

 

Dipropyl ketone 123-19-3 50 235          

 

Diquat 85-00-7   0.5          

 

Di-sec octyl phthalate (Di-2-ethylhexyl-phthalate) 117-81-7   5   10      

 

Disulfram 97-77-8   2          

table of contents

Table Z-1 - Page 8 
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Disulfoton 298-04-4   0.1         X

 

2,6-Di-tert-butyl-p-cresol 128-37-0   10          

 

Diuron 330-54-1   10          

 

Divinyl benzene 1321-74-0 10 50          

 

Emery
  Total dust
  Respirable fraction
112-62-9  
 
  10
  5
         

 

Endosulfan 115-29-7   0.1         X

 

Endrin 72-20-8   0.1         X

 

Epichlorohydrin 106-89-8 2 8         X

 

EPN 2104-64-5   0.5         X

 

1,2-Epoxypropane; see Propylene oxide                

 

2,3-Epoxy-1-propanol; see Glycidol                

 

Ethanethiol; see Ethyl mercaptan                

 

Ethanolamine 141-43-5 3 8 6 15      

 

Ethion 563-12-2   0.4         X

 

2-Ethoxyethanol 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 5 20 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 100-41-4 100 435 125 545      

 

Ethyl bromide 74-96-4 200 890 250 1110      

 

Ethyl butyl ketone (3-Heptanone) 106-35-4 50 230          

 

Ethyl chloride 75-00-3 1000 2600          

 

Ethyl ether 60-29-7 400 1200 500 1500      

 

Ethyl formate 109-94-4 100 300          

 

Ethyl mercaptan 75-08-1 0.5 1          

 

Ethyl silicate 78-10-4 10 85          

 

Ethylene chlorohydrin 107-07-3         1 3 X

 

Ethylenediamine 107-15-3 10 25          

 

Ethylene dibromide 106-93-4 Table Z-2 Table Z-2 Table Z-2 Table Z-2 Table Z-2 Table Z-2 Table
Z-2

 

Ethylene dichloride 107-06-2 1 4 2 8      

 

Ethylene glycol 107-21-1         50 125  

 

Ethylene glycol dinitrate 628-96-6       0.1     X

 

Ethylene glycol methyl acetate; see Methyl cellosolve acetate Ethyleneimine; see 1910.1012 151-56-4              

 

Ethylene oxide; see 1910.1047 75-21-8              

 

Ethylidene chloride; see 1,1-Dichlorethane                

table of contents

Table Z-1 - Page 9
print page 9 (PDF, 12KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Ethylidene norbornene 16219-75-3         5 25  

 

N-Ethylmorpholine 100-74-3 5 23         X

 

Fenamiphos 22224-92-6   0.1         X

 

Fensulfothion (Dasanit) 115-90-2   0.1          

 

Fenthion 55-38-9   0.2         X

 

Ferbam
  Total dust
14484-64-1  
 
  10
         

 

Ferrovanadium dust 12604-58-9   1   3      

 

Fluorides (as F) varies with compound   2.5          

 

Fluorine 7782-41-4 0.1 0.2          

 

Fluorotrichloromethane (Trichlorofluoromethane) 75-69-4         1000 5600  

 

Fonofos 944-22-9   0.1         X

 

Formaldehyde; see 1910.1048; see Table Z-2 for operations or sectors excluded from 1910.1048 or for which limit(s) is(are) stayed. 50-00-0              

 

Formamide 75-12-7 20 30 30 45      

 

Formic acid 64-18-6 5 9          

 

Furfural 98-01-1 2 8         X

 

Furfuryl alcohol 98-00-0 10 40 15 60     X

 

Gasoline 8006-61-9 300 900 500 1500      

 

Germanium tetrahydride 7782-65-2 0.2 0.6          

 

Glutaraldehyde 111-30-8         0.2 0.8  

 

Glycerin (mist)
  Total dust
  Respirable fraction
56-81-5  
 
  10
  5
         

 

Glycidol 556-52-5 25 75          

 

Glycol monoethyl ether; see 2-Ethoxyethanol                

 

Grain dust (oat, wheat, barley)     10          

 

Graphite, natural respirable dust 7782-42-5   2.5          

 

Graphite, synthetic
  Total dust
  Respirable fraction
   
 
  10
  5
         

 

GuthionR; see Azinphos methyl                

 

Gypsum
  Total dust
  Respirable fraction
13397-24-5  
 
  15
  5
         

 

Hafnium 7440-58-6   0.5          

 

Heptachlor 76-44-8   0.5         X

 

Heptane (n-Heptane) 142-82-5 400 1600 500 2000      

 

Hexachlorobutadiene 87-68-3 0.02 0.24          

 

Hexachlorocyclo-pentadiene 77-47-4 0.01 0.1          

table of contents

Table Z-1 - Page 10 
print page 10 (PDF, 13KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Hexachloroethane 67-72-1 1 10         X

 

Hexachloronaphthalene 1335-87-1   0.2         X

 

Hexafluoroacetone 684-16-2 0.1 0.7         X

 

n-Hexane 110-54-3 50 180          

 

Hexane isomers varies with compound 500 1800 1000 3600      

 

2-Hexanone (Methyl n-butyl ketone) 591-78-6 5 20          

 

Hexone (Methyl isobutyl ketone) 108-10-1 50 205 75 300      

 

sec-Hexyl acetate 108-84-9 50 300          

 

Hexylene glycol 107-41-5         25 125  

 

Hydrazine 302-01-2 0.1 0.1         X

 

Hydrogenated terphenyls 61788-32-7 0.5 5          

 

Hydrogen bromide 10035-10-6         3 10  

 

Hydrogen chloride 7647-01-0         5 7  

 

Hydrogen cyanide 74-90-8     4.7 5     X

 

Hydrogen fluoride (as F) 7664-39-3 3 6          

 

Hydrogen peroxide 7722-84-1 1 1.4          

 

Hydrogen selenide (as Se) 7783-07-5 0.05 0.2          

 

Hydrogen sulfide 7783-06-4 10 14 15 21      

 

Hydroquinone 123-31-9   2          

 

2-Hydroxypropyl acrylate 999-61-1 0.5 3         X

 

Indene 95-13-6 10 45          

 

Indium and compounds (as In) 7440-74-6   0.1          

 

Iodine 7553-56-2         0.1 1  

 

Iodoform 75-47-8 0.6 10          

 

Iron oxide dust and fume (as Fe)
  Total particulate
   
 
  10
         

 

Iron pentacarbonyl (as Fe) 13463-40-6 0.1 0.8 0.2 1.6      

 

Iron salts (soluble) (as Fe) varies with compound   1          

 

Isomyl acetate 123-92-2 100 525          

 

Isomyl alcohol (primary and secondary) 123-51-3 100 360 125 450      

 

Isobutyl acetate 110-19-0 150 700          

 

Isobutyl alcohol 78-83-1 50 150          

 

Isooctyl alcohol 26952-21-6 50 270         X

 

Isophorone 78-59-1 4 23          

 

Isophorone diisocyanate 4098-71-6 0.005   0.02       X

 

2-isopropoxyethanol 109-59-1 25 105          

 

Isopropyl acetate 108-21-4 250 950 310 1185      

 

Isopropyl alcohol 67-63-0 400 980 500 1225      

 

Isopropylamine 75-31-0 5 12 10 24      

 

N-isopropylaniline 768-52-5 2 10         X

table of contents

Table Z-1 - Page 11 
print page 11 (PDF, 12KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Isopropyl ether 108-20-3 500 2100          

 

Isopropyl glycidyl ether (IGE) 4016-14-2 50 240 75 360      

 

Kaolin
  Total dust
  Respirable fraction
   
 
  10
  5
         

 

Ketene 463-51-4 0.5 0.9 1.5 3      

 

Lead inorganic (as Pb); see 1910.1025 7439-92-1              

 

Limestone
  Total dust
  Respirable fraction
1317-65-3  
 
  15
  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
  Total dust
  Respirable fraction
546-93-0  
 
  15
  5
         

 

Magnesium oxide fume
  Total particulate
1309-48-4  
 
  10
         

 

Malathion
  Total dust
121-75-5  
 
  10
        X

 

Maleic anhydride 108-31-6 0.25 1          

 

Manganese compounds (as Mn) 7439-96-5           5  

 

Manganese fume (as Mn) 7439-96-5   1   3      

 

Manganese cyclopenta-dienyl tricarbonyl (as Mn) 12079-65-1   0.1         X

 

Manganese tetroxide (as Mn) 1317-35-7   1          

 

Marble
  Total dust
  Respirable fraction
1317-65-3  
 
  15
  5
         

 

Mercury (aryl and inorganic) (as Hg) 7439-97-6           0.1 X

 

Mercury (organo) alkyl compounds (as Hg) 7439-97-6   0.01   0.03     X

 

Mercury (vapor) (as Hg) 7439-97-6   0.05         X

 

Mesityl oxide 141-79-7 15 60 25 100      

 

Methacrylic acid 79-41-4 20 70         X

 

Methanethiol; see Methyl mercaptan                

 

Methomyl (Lannate) 16752-77-5   2.5          

 

Methoxychlor
  Total dust
72-43-5  
 
  10
         

 

2-Methoxyethanol; see Methyl cellosolve                

 

4-Methoxyphenol 150-76-5   5          

 

Methyl acetate 79-20-9 200 610 250 760      

 

Methyl acetylene (Propyne) 74-99-7 1000 1650          

 

Methyl acetylene propadiene mixture (MAPP)   1000 1800 1250 2250      

table of contents

Table Z-1 - Page 12 
print page 12 (PDF, 12KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Methyl acrylate 96-33-3 10 35         X

 

Methylacrylonitrile 126-98-7 1 3         X

 

Methylal (Dimethoxy-methane) 109-87-5 1000 3100          

 

Methyl alcohol 67-56-1 200 260 250 325     X

 

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 5 20         X

 

Methyl butyl ketone; see 2-Hexanone                

 

Methyl cellosolve; (2-Methoxyethanol) 109-86-4 25 80         X

 

Methyl cellosolve acetate; (2-Methoxyethyl acetate) 110-49-6 25 120         X

 

Methyl chloride 74-87-3 50 105 100 210      

 

Methyl chloroform (1,1,1-Trichloroethane) 71-55-6 350 1900 450 2450      

 

Methyl 2-cyanoacrylate 137-05-3 2 8 4 16      

 

Methylcyclohexane 108-87-2 400 1600          

 

Methylcyclohexanol 25639-42-3 50 235          

 

o-Methylcyclohexanone 583-60-8 50 230 75 345     X

 

Methylcyclopentadienyl manganese tricarbonyl (as Mn) 12108-13-3   0.2         X

 

Methyl demeton 8022-00-2   0.5         X

 

4,4-Methylene bis (2-chloroaniline) (MBOCA) 101-14-4 0.02 0.22         X

 

Methylene bis (4-cyclohexylisocyanate) 5124-30-1         0.01 0.11 X

 

Methylene chloride 75-09-2 Table Z-2   Table Z-2   Table Z-2    

 

Methyl ethyl ketone peroxide (MEKP) 1338-23-4         0.7 5  

 

Methyl formate 107-31-3 100 250 150 375      

 

Methyl hydrazine (Monomethyl hydrazine) 60-34-4         0.2 0.35 X

 

Methyl iodide 74-88-4 2 10         X

 

Methyl isoamyl ketone 110-12-3 50 240          

 

Methyl isobutyl carbinol 108-11-2 25 100 40 165     X

 

Methyl isobutyl ketone; see Hexone                

 

Methyl isocyanate 624-83-9 0.02 0.05         X

 

Methyl isopropyl ketone 563-80-4 200 705          

 

Methyl mercaptan 74-93-1 0.5 1          

 

Methyl methacrylate 80-62-6 100 410          

 

Methyl parathion 298-00-0   0.2         X

 

Methyl propyl ketone; see 2-Pentanone                

 

Methyl silicate 681-84-5 1 6          

 

alpha-Methyl styrene 98-83-9 50 240 100 485      

 

Methylene bisphenyl isocyanate (MDI) 101-68-8         0.02 0.2  

 

Metribuzin 21087-64-9   5          

 

Mica; see Silicates                

table of contents

Table Z-1 - Page 13 
print page 13 (PDF, 12KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Molybdenum (as Mo)
  Soluble compounds
  Insoluble Compounds
     Total dust
7439-98-7  
 
  5
   
  10
         

 

Monocrotophos (AzodrinR) 6923-22-4   0.25          

 

Monomethyl aniline 100-61-8 0.5 2         X

 

Morpholine 110-91-8 20 70 30 105     X

 

Naphtha (Coal tar) 8030-30-6 100 400          

 

Naphthalene 91-20-3 10 50 15 75      

 

alpha-Naphthylamine; see 1910.1004 134-32-7              

 

beta-Naphthylamine; see 1910.1009 91-59-8              

 

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   0.1          

 

Nicotine 54-11-5   0.5 X        

 

Nitric acid 7697-37-2 2 5 4 10      

 

Nitric oxide 10102-43-9 25 30          

 

p-Nitroaniline 100-01-6   3         X

 

Nitrobenzene 98-95-3 1 5         X

 

p-Nitrochlorobenzene 100-00-5   1         X

 

4-Nitrodiphenyl; see 1910.1003 92-93-3              

 

Nitroethane 79-24-3 100 310          

 

Nitrogen dioxide 10102-44-0     1 1.8      

 

Nitrogen trifluoride 7783-54-2 10 29          

 

Nitroglycerin 55-63-0       0.1     X

 

Nitromethane 75-52-5 100 250          

 

1-Nitropropane 108-03-2 25 90          

 

2-Nitropropane 79-46-9 10 35          

 

N-Nitrosodimethylamine; see 1910.1016 62-75-9              

 

Nitrotoluene
  o-isomer
  m-isomer
  p-isomer
 
  88-72-2
  99-08-1
  99-99-0
2 11         X

 

Nitrotrichloromethane; see Chloropicrin                

 

Nonane 111-84-2 200 1050          

 

Octachloronaphthalene 2234-13-1   0.1   0.3     X

 

Octane 111-65-9 300 1450 375 1800      

 

Oil mist, mineral 8012-95-1   5          

 

Osmium tetroxide (as Os) 20816-12-0 0.0002 0.002 0.0006 0.006      

 

Oxalic acid 144-62-7   1   2      

 

Oxygen difluoride 7783-41-7         0.05 0.1  

 

Ozone 10028-15-6 0.1 0.2 0.3 0.6      

table of contents

Table Z-1 - Page 14 
print page 14 (PDF, 12KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Paraffin wax fume 8002-74-2   2          

 

Paraquat, respirable dust
  1910-42-5
  4685-14-7
  2074-50-2
 
0.1
 
 
       
X
 
 

 

Parathion 56-38-2   0.1         X

 

Particulates not otherwise regulated
 
Total dust
Respirable fraction
   
 
15
5
         

 

Pentaborane 19624-22-7 0.005 0.01 0.015 0.03      

 

Pentachloronaphthalene 1321-64-8   0.5         X

 

Pentachlorophenol 87-86-5   0.5         X

 

Pentaerythritol
 
Total dust
Respirable fraction
115-77-5  
 
10
5
         

 

Pentane 109-66-0 600 1800 750 2250      

 

2-Pentanone (Methyl propyl ketone) 107-87-9 200 700 250 875      

 

Perchloroethylene (Tetrachloroethylene) 127-18-4 25 170          

 

Perchloromethyl mercaptan 594-42-3 0.1 0.8          

 

Perchloryl fluoride 7616-94-6 3 14 6 28      

 

Perlite
 
Total dust
Respirable fraction
   
 
15
5
         

 

Petroleum distillates (Naphtha) 8002-05-9 400 1600          

 

Phenol 108-95-2 5 19         X

 

Phenothiazine 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 1 6          

 

Phenylhydrazine 100-63-0 5 20 10 45     X

 

Phenyl mercaptan 108-98-5 0.5 2          

 

Phenylphosphine 638-21-1         0.05 0.25  

 

Phorate 298-02-2   0.05   0.2     X

 

Phosdrin (MevinphosR) 7786-34-7 0.01 0.1 0.03 0.3     X

 

Phosgene (Carbonyl chloride) 75-44-5 0.1 0.4          

 

Phosphine 7803-51-2 0.3 0.4 1 1      

 

Phosphoric acid 7664-38-2   1   3      

 

Phosphorus (yellow) 7723-14-0   0.1          

 

Phosphorus oxychloride 10025-87-3 0.1 0.6          

 

Phosphorus pentachloride 10026-13-8   1          

 

Phosphorus pentasulfide 1314-80-3   1   3      

table of contents

Table Z-1 - Page 15 
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Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Phosphorus trichloride 7719-12-2 0.2 1.5 0.5 3      

 

Phthalic anhydride 85-44-9 1 6          

 

m-Phthalodinitrile 626-17-5   5          

 

Picloram
 
Total dust
Respirable fraction
   
 
10
5
         

 

Picric acid 88-89-1   0.1         X

 

Poperazine dihydro-chloride 142-64-3   5          

 

Pindone (2-Pivalyl-1,3-indandione) 83-26-1   0.1          

 

Plaster of paris
 
Total dust
Respirable fraction
24699-65-0  
 
15
5
         

 

Platinum (as Pt)
 
 Metal
Soluble salts
7440-06-4  
 
1
0.002
         

 

Portland cement
 
Total dust
Respirable fraction
65997-15-1  
 
10
5
         

 

Potassium hydroxide 1310-58-3           2  

 

Propane 74-98-6 1000 1800          

 

Propargyl alcohol 107-19-7 1 2         X

 

beta-Propriolactone; see 1910.1013 57-57-8              

 

Propionic acid 79-09-4 10 30          

 

Propoxur (Baygon) 114-26-1   0.5          

 

n-Propyl acetate 109-60-4 200 840 250 1050      

 

n-Propyl alcohol 71-23-8 200 500 250 625      

 

n-Propyl nitrate 627-13-4 25 105 40 170      

 

Propylene dichloride 78-87-5 75 350 110 510      

 

Propylene glycol dinitrate 6423-43-4 0.5 0.36          

 

Propylene glycol monomethyl ether 107-98-2 100 360 150 540      

 

Propylene imine 75-55-8 2 5         X

 

Propylene oxide 75-56-9 20 50          

 

Propyne; see Methyl acetylene                

 

Pyrethrum 8003-34-7   5          

 

Pyridine 110-86-1 5 15          

 

Quinone 106-51-4 0.1 0.4          

 

Resorcinol 108-46-3 10 45 20 90      

 

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          

 

Rosin core solder pyrolysis products, as formaldehyde     0.1          

 

Rotenone 83-79-4   5          

table of contents

Table Z-1 - Page 16 
print page 16 (PDF, 8KB)

Substance CAS No.
(f)
TWA STEL (c) Ceiling Skin Designation
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)
ppm
(a)
mg/m3
(b)

 

Rouge
 
Total dust
Respirable fraction
   
 
10
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     6          

 

Silica, amorphous, diatomaceous earth, containing less than 1% crystalline silica 61790-53-2   6          

 

Silica, crystalline cristobalite, (as quartz), respirable dust 14464-46-1   0.05          

 

Silica, crystalline quartz, (as quartz) respirable dust 14808-60-7   0.1          

 

Silica, crystalline tripoli (as quartz), respirable dust 1317-95-9   0.1          

 

Silica, crystalline tridymite, (as quartz) respirable dust 15468-32-3   0.05          

 

Silica, fused, respirable dust