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Acute Reference Exposure Levels Summary Table and Table of Hazard Index Target Organs

Table A-1.Acute Reference Exposure Levels (RELs), Averaging Times, and Toxicologic Endpoints

Chemical Name (CAS #)

REL
(µg/m3)

Avg
time
(h)

Sp.1

Toxicologic Endpoints

Severity2

Acrolein
(107-02-8)

1.9 x 10-1

1

H

Eye Irritation Mild
Acrylic Acid
(79-10-7)

6 x 103

1

R

Respiratory Irritation Mild
Ammonia
(7664-41-7)

3.2 x 103

1

H

Eye and Respiratory Irritation Mild
Arsenic and Inorganic Arsenic Compounds

1.9 x 10-1

4

M

Reproductive/
Developmental		 Severe
Arsine
(7784-42-1)

1.6 x 102

1

M

Hematologic System Severe
Benzene
(71-43-2)

1.3 x 103

6

R

Reproductive/
Developmental		 Severe
Benzyl Chloride (100-44-7)

2.4 x 102

1

M&R

Eye and Respiratory Irritation Mild
Carbon Disulfide (75-15-0)

6.2 x 103

6

R

Reproductive/
Developmental		 Severe
Carbon Monoxide3
(630-08-0)

2.3 x 104

1

H

Cardiovascular System Mild
Carbon Tetrachloride
(56-23-5)

1.9 x 103

7

R

Reproductive/
Developmental		 Severe
Chlorine
(7782-50-5)

2.1 x 102

1

H

Respiratory Irritation Mild
Chloroform
(67-66-3)

1.5 x 102

7

R

Reproductive/
Developmental		 Severe
Chloropicrin
(76-06-2)

2.9 x 101

1

M

Eye and Respiratory Irritation Mild
Copper and Compounds

1 x 102

1

H

Respiratory Irritation Mild
1,4-Dioxane
(123-91-1)

3 x 103

1

H

Eye and Respiratory Irritation Mild
Epichlorohydrin (106-89-8)

1.3 x 103

1

H

Eye and Respiratory Irritation Mild
Ethylene Glycol Monobutyl Ether (111-76-2)

1.4 x 104

1

H

Eye and Respiratory Irritation Mild
Ethylene Glycol Monoethyl Ether (110-80-5)

3.7 x 102

6

R

Reproductive/
Developmental		 Severe
Ethylene Glycol Monoethyl Ether Acetate
(111-15-9)

1.4 x 102

6

Rb

Reproductive/
Developmental		 Severe
Ethylene Glycol Monomethyl Ether (109-86-4)

9.3 x 101

6

R

Reproductive/
Developmental 		Severe
Formaldehyde (50-00-0)

9.4 x 101

1

H

Eye Irritation Mild
Hydrogen chloride (7647-01-0)

2.1 x 103

1

H

Eye and Respiratory Irritation Mild
Hydrogen Cyanide
(74-90-8)

3.4 x 102

1

Mk

CNS4 - serious Severe
Hydrogen Fluoride (7664-39-3)

2.4 x 102

1

H

Eye and Respiratory Irritation Mild
Hydrogen Selenide

5 x 100

1

GP

Eye and Respiratory Irritation Mild
Hydrogen Sulfide (7783-06-4)3

4.2 x 101

1

H

Respiratory Irritation Mild
Isopropyl Alcohol (67-63-0)

3.2 x 103

1

H

Eye and Respiratory Irritation Mild
Mercury (Inorganic)
(7439-97-6)

1.8 x 100

1

R

Reproductive/
Developmental		 Severe
Methanol
(67-56-1)

2.8 x 104

1

H

CNS4 - mild Mild
Methyl Bromide (74-83-9)

3.9 x 103

1

H

CNS- mild (anorexia, nausea, headache; Mild
Methyl Chloroform (71-55-6)

6.8 x 104

1

H

CNS - mild Mild
Methyl Ethyl Ketone
(78-93-3)

1.3 x 104

1

H

Eye and Respiratory Irritation Mild
Methylene Chloride
(75-9-2)

1.4 x 104

1

H

CNS - mild Mild
Nickel and Nickel Compounds

6 x 100

1

H

Respiratory Irritation; Immune Response Mild
Nitric Acid
(7697-37-2)

8.6 x 101

1

H

Respiratory Irritation Mild
Nitrogen Dioxide3
(10102-44-0)

4.7 x 102

1

H

Respiratory Irritation Mild
Ozone3
(10028-15-6)

1.8 x 102

1

H

Eye and Respiratory Irritation Mild
Perchloroethylene (127-18-4)

2 x 104

1

H

CNS - mild; Eye and Respiratory Irritation Mild
Phenol
(108-95-2)

5.8 x 103

1

H

Eye and Respiratory Irritation Mild
Phosgene
(75-44-5)

4 x 100

1

R

Respiratory Irritation Mild
Propylene Oxide (75-56-9)

3.1 x 103

1

M

Eye and Respiratory Irritation Mild
Sodium Hydroxide (1310-93-2)

8 x 100

1

H

Skin, Eye, and Respiratory Irritation Mild
Styrene
(100-42-5)

2.1 x 104

1

H

Eye and Respiratory Irritation Mild
Sulfates3

1.2 x 102

1

H

Respiratory Irritation Mild
Sulfur Dioxide3
(7446-09-5)

6.6 x 102

1

H

Respiratory Irritation Mild
Sulfuric Acid and Oleum

1.2 x 102

1

H

Respiratory Irritation Mild
Toluene
(108-88-3)

3.7 x 104

1

H

CNS - mild;
Eye and Respiratory Irritation		 Mild
Triethylamine (121-44-8)

2.8 x 103

1

H

CNS - mild; Eye Irritation Mild
Vanadium Pentoxide
(1314-62-1)

3 x 101

1

H

Respiratory Irritation Mild
Vinyl Chloride
(75-01-4)

1.8 x 105

1

H

CNS - mild; Eye and Respiratory Irritation Mild
Xylenes (m,o,p-isomers)

2.2 x 104

1

H

Eye and Respiratory Irritation Mild

1 Species used in key study for REL development: D = dog; GP = guinea pig: H = human; M = mouse; Mk = monkey; R = rat; Rb = rabbit

2 Refers to effect severity levels-- see Hazard Identification section of main text or Table 6

3 California Ambient Air Quality Standard

4 CNS = Central Nervous System.

Table A-2. Hazard Index Target Organs

Chemical Name
(CAS #)

Target Organs

Acrolein (107-02-8) Respiratory System; Eye
Acrylic Acid (79-10-7) Respiratory System; Eye
Ammonia (7664-41-7) Respiratory System; Eye
Arsenic and Inorganic Arsenic Compounds Reproductive/Developmental
Arsine (7784-42-1) Hematologic System
Benzene (71-43-2) Reproductive/developmental; Immune System; Hematologic System;
Benzyl Chloride
(100-44-7)		 Respiratory System; Eye
Carbon Disulfide
(75-15-0)		 Reproductive/Developmental; Nervous System
Carbon Monoxide (630-08-0) Cardiovascular System
Carbon Tetrachloride (56-23-5) Reproductive/Developmental; Nervous System; Alimentary Tract
Chlorine (7782-50-5) Respiratory System; Eye
Chloroform (67-66-3) Nervous System;
Reproductive/Developmental
Chloropicrin (76-06-2) Respiratory System; Eye
Copper and Compounds Respiratory System
1,4-Dioxane (123-91-1) Respiratory System; Eye
Epichlorohydrin
(106-89-8)		 Respiratory System; Eye
Ethylene Glycol Monobutyl Ether
(111-76-2)

Respiratory System; Eye

Ethylene Glycol Monoethyl Ether
(110-80-5)		 Reproductive/Developmental
Ethylene Glycol Monoethyl Ether Acetate (111-15-9) Reproductive/Developmental; Nervous System
Ethylene Glycol Monomethyl Ether (109-86-4) Reproductive/Developmental
Formaldehyde
(50-00-0)		 Eye; Respiratory System; Immune System
Hydrogen Chloride (7647-01-0) Respiratory System; Eye
Hydrogen Cyanide (74-90-8) Nervous System
Hydrogen Fluoride (7664-39-3) Respiratory System; Eye
Hydrogen Sulfide (7783-06-4) Headache and Nausea in Response to Odor
Isopropyl Alcohol
(67-63-0)		 Respiratory System; Eye
Mercury (Inorganic)
(7439-97-6)		 Reproductive/Developmental
Methanol (67-56-1) Nervous System
Methyl Bromide
(74-83-9)		 Nervous System; Respiratory Irritation; Reproductive/developmental
Methyl Chloroform
(71-55-6)		 Nervous System
Methyl Ethyl Ketone (78-93-3) Respiratory System; Eye
Methylene Chloride (75-9-2) Nervous System
Nickel and Nickel Compounds Respiratory System; Immune System
Nitric Acid (7697-37-2) Respiratory System
Nitrogen Dioxide
(10102-44-0)		 Respiratory System
Ozone (10028-15-6) Eye; Respiratory System
Perchloroethylene (127-18-4) Nervous system; Eye; Respiratory System
Phenol (108-95-2) Respiratory System; Eye
Phosgene (75-44-5) Respiratory System
Propylene Oxide
(75-56-9)		 Respiratory System; Eye; Reproductive/developmental
Selenium: He2S Respiratory System; Eye
Sodium Hydroxide (1310-93-2) Eye; Skin; Respiratory System
Styrene (100-42-5) Respiratory System; Eye;
Sulfates Respiratory System
Sulfur Dioxide
(7446-09-5)		 Respiratory System
Sulfuric Acid and Oleum Respiratory System
Toluene (108-88-3) Nervous System; Eye; Respiratory System; Reproductive/developmental??
Triethylamine
(121-44-8)		 Nervous System; Eye
Vanadium Pentoxide
(1314-62-1)		 Respiratory System; Eye
Vinyl Chloride
(75-01-4)		 Nervous System; Eye; Respiratory System
Xylenes
(m,o,p-isomers)		 Eye; Respiratory System
 
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