We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Chemical Priority Lists for Acute Exposure Guideline Levels (AEGLs)

The Acute Exposure Guideline Levels (AEGLs) Program develops AEGL values for chemicals that can potentially cause dangerous inhalation exposures to persons through accidental releases to air or by means of a terrorist action.

AEGL values are developed for chemicals from a priority list that is generated from nominations by stakeholder organizations. While AEGL development focuses primarily on the priority-listed chemicals, occasionally other chemicals become of interest and are nominated for priority consideration.

The First AEGL Chemical Priority List of 85 chemicals appeared in the Federal Register on May 21, 1997. Fifteen chemicals were subsequently added and are included in this Web site listing.  See the May 21, 1997 Federal Register notice. 

The Second AEGL Chemical Priority List was published in the Federal Register on May 31, 2002, and contained 371 priority chemicals, 137 of which were considered a higher priority than the other 234 chemicals.  See the May 31, 2002 Federal Register Notice.

All 471 AEGL priority chemicals are included below:

The First AEGL Chemical Priority List appeared in the May 21, 1997 Federal Register and listed 85 chemicals.

An additional 15 chemicals were added to this list subsequently. All 100 First AEGL Chemical Priority List chemicals were viewed as high priority for AEGL development based on their nomination by stakeholder of the AEGL Committee and the overlapping interest among many different organizations.

CAS No.                               Chemical Name

56-23-5................................... Carbon tetrachloride
57-14-7................................... 1,1-Dimethyl hydrazine
60-34-4................................... Methyl hydrazine
62-53-3................................... Aniline
67-56-1................................... Methanol
67-66-3................................... Chloroform
68-12-2................................... Dimethylformamide
71-43-2................................... Benzene
74-90-8................................... Hydrogen cyanide
74-93-1................................... Methyl mercaptan
75-09-2................................... Methylene chloride
75-21-8................................... Ethylene oxide
75-44-5................................... Phosgene
75-55-8................................... Propyleneimine
75-56-9................................... Propylene oxide
75-74-1................................... Tetramethyllead
75-77-4................................... Trimethychlorosilane
75-78-5................................... Dimethyldichlorosilane
75-79-6................................... Methyltrichlorosilane
75-86-5................................... Acetone cyanohydrin
77-81-6................................... Tabun (GA)
78-82-0................................... Isobutyronitrile
78-93-3................................... Methyl ethyl ketone
79-01-6................................... Trichloroethylene
79-10-7................................... Acrylic acid
79-11-8................................... (mono-)Chloroacetic acid
79-21-0................................... Peracetic acid
79-22-1................................... Methyl chloroformate
91-08-7................................... Toluene 2,6-diisocyanate
96-64-0................................... Soman (GD)
106-89-8................................. Epichlorohydrin
107-02-8................................. Acrolein
107-11-9................................. Allyl amine
107-12-0................................. Propionitrile
107-15-3................................. Ethylenediamine
107-18-6................................. Allyl alcohol
107-30-2................................. Chloromethyl methyl ether
107-44-8................................. Sarin (GB)
108-23-6................................. Isopropyl chloroformate
108-88-3................................. Toluene
108-91-8................................. Cyclohexylamine
108-95-2................................. Phenol
109-61-5................................. Propyl chloroformate
110-00-9................................. Furan
110-89-4................................. Piperidine
123-73-9................................. Crotonaldehyde, (E)
123-91-1................................. 1,4-Dioxane
126-98-7................................. Methacrylonitrile
127-18-4................................. Tetrachloroethylene
151-56-4................................. Ethyleneimine
302-01-2................................. Hydrazine
329-99-7................................. Cyclohexylmethyl phosphono fluoridate GF
353-42-4................................. Boron triflouride compound with methyl ether (note: boron trifluoride CAS # is 7637-07-2)
505-60-2................................. Sulfur mustard
506-77-7................................. Cyanogen chloride
509-14-8................................. Tetranitromethane
540-59-0................................. 1,2-Dichloroethylene
540-73-8................................. 1,2-Dimethylhydrazine
584-84-9................................. Toluene 2,4-diisocyanate
594-42-3................................. Perchloromethylmercaptan
624-83-9................................. Methyl isocyanate
630-08-0................................. Carbon monoxide
811-97-2................................. HFC 134A (1,1,1,2-Tetrafluoroethane)
814-68-6................................. Acrylyl chloride
1330-20-7............................... Xylenes (mixed)
1717-00-6............................... HCFC 141b (1,1-Dichloro-1-fluoroethane)
4170-30-3............................... Crotonaldehyde
6423-43-4............................... Otto Fuel II
7446-09-5............................... Sulfur dioxide
7446-11-9............................... Sulfur trioxide
7647-01-0............................... Hydrogen chloride
7647-01-0............................... Hydrochloric acid
7664-39-3............................... Hydrogen fluoride
7664-41-7............................... Ammonia
7664-93-9............................... Sulfuric acid
7697-37-2............................... Nitric acid
7719-12-2............................... Phosphorus trichloride
7726-95-6............................... Bromine
7782-41-4............................... Fluorine
7782-50-5............................... Chlorine
7783-06-4............................... Hydrogen sulfide
7783-60-0............................... Sulfur tetrafluoride
7783-81-5............................... Uranium hexafluoride
7784-34-1............................... Arsenous trichloride
7784-42-1............................... Arsine
7790-91-2............................... Chlorine trifluoride
7803-51-2............................... Phosphine
8014-95-7............................... Oleum
10025-87-3.............................. Phosphorus oxychloride
10049-04-4.............................. Chlorine dioxide
10102-43-9.............................. Nitric oxide
10102-44-0.............................. Nitrogen dioxide
10294-34-5.............................. Boron trichloride
13463-39-3.............................. Nickel carbonyl
13463-40-6.............................. Iron, pentacarbonyl-
19287-45-7.............................. Diborane
25323-89-1.............................. Trichloroethane
50782-69-9.............................. VX
163702-07-6............................ Methyl nonafluorobutyl ether (HFE 7100 component)
163702-08-7............................ Methyl nonafluorobutyl ether (HFE 7100 component)

The Second Priority List of AEGL chemicals, with 371 priority chemicals, is a composite of numerous priority lists of acutely toxic chemicals. AEGL values were developed for chemicals from this list as well as those in the First Priority List. The list was assembled from the individual lists of chemicals nominated by NAC/AEGL Committee member organizations for AEGL development. There are 137 chemicals on this list of 371 priority chemicals that were considered a higher priority (indicated by an asterisk below), based on considerations of toxicity, volatility, presence on numerous organization chemical lists, and other factors.

Second List of AEGL Priority Chemicals for Guideline Development

CAS No.                               Chemical Name

50-00-0................................... Formaldehyde*
50-29-3................................... 4,4'-DDT
50-32-8................................... Benzo(a)pyrene*
54-11-5................................... Nicotine
56-38-2................................... Parathion*
56-55-3................................... Benzo(a)anthracene
56-72-4................................... Coumaphos
57-24-9................................... Strychnine*
57-57-8................................... Beta-Propiolactone
57-74-9................................... Chlordane*
58-89-9................................... Lindane (hexachlorocyclohexane)
60-29-7................................... Ethyl ether
60-51-5................................... Dimethoate
60-57-1................................... Dieldrin
62-38-4................................... Phenylmercuric acetate*
62-73-7................................... Dichlorvos
62-74-8................................... Sodium fluoroacetate*
62-75-9................................... Nitrosodimethylamine
64-18-6................................... Formic acid
64-19-7................................... Acetic acid
67-64-1................................... Acetone*
74-82-8................................... Methane
74-83-9................................... Methyl bromide*
74-87-3................................... Methyl chloride*
74-88-4................................... Methyl iodide
74-89-5................................... Methyl amine*
74-98-6................................... Propane*
75-00-3................................... Chloroethane
75-01-4................................... Vinyl chloride*
75-02-5................................... Vinyl fluoride
75-04-7................................... Ethyl amine*
75-05-8................................... Acetonitrile
75-07-0................................... Acetaldehyde*
75-08-1................................... Ethyl mercaptan*
75-12-7................................... Formamide
75-15-0................................... Carbon disulfide*
75-18-3................................... Dimethyl sulfide
75-25-2................................... Bromoform
75-34-3................................... 1,1-Dichloroethane
75-36-5................................... Acetyl chloride*
75-50-3................................... Trimethylamine*
75-54-7................................... Methyl dichlorosilane*
75-65-0................................... t-Butyl alcohol
75-93-4................................... Methyl sulfate
76-02-8................................... Trichloroacetyl chloride*
76-06-2................................... Chloropicrin*
76-44-8................................... Heptachlor
77-47-4................................... Hexachlorocyclopentadiene
77-78-1................................... Dimethyl sulfate*
78-00-2................................... Tetraethyl lead
78-71-7................................... Oxetane, 3,3- bis(chloromethyl)-
78-85-3................................... Methacrylaldehyde*
78-87-5................................... 1,2-Dichloropropane
78-94-4................................... Methyl vinyl ketone*
78-95-5................................... Chloroacetone (stabilized)*
78-97-7................................... Lactonitrile
79-04-9................................... Chloroacetyl chloride*
79-06-1................................... Crylamide
79-09-4................................... Propionic acid
79-14-1................................... Glycolic acid
79-19-6................................... Thiosemicarbazide
79-38-9................................... Trifluorochloroethylene
79-41-4................................... Methacrylic acid*
79-57-2................................... Terramycin*
80-15-9................................... Cumene hydroperoxide
80-56-8................................... alpha-Pinene
80-62-6................................... Methyl methacrylate*
80-63-7................................... Methyl 2-chloroacrylate
81-81-2................................... Warfarin
82-66-6................................... Diphacinone
84-66-2................................... Diethyl phthalate
84-74-2................................... di-n-Butyl phthalate
85-68-7................................... Butyl benzyl phthalate
86-50-0................................... Azinphos-methyl*
86-74-8................................... Carbazole
87-86-5................................... Pentachlorophenol
92-52-4................................... Biphenyl
94-75-7................................... 2,4-Dichlorophenyoxy acetic acid
95-48-7................................... o-Cresol
95-63-6................................... Trimethyl benzene
96-29-7................................... 2-Butanone oxime
97-02-9................................... 2,4-Dinitroaniline*
98-05-5................................... Phenyl arsonic acid
98-07-7................................... Benzyl trichloride
98-09-9................................... Benzenesulfonyl chloride
98-13-5................................... Trichlorophenyl silane
98-16-8................................... 3-(Trifluoromethyl) Aniline
98-82-8................................... Cumene
98-87-3................................... Benzal chloride
98-88-4................................... Benzoyl chloride
98-95-3................................... Nitrobenzene
100-14-1.................................. Benzene, 1-(chloromethyl)-4- nitro-
100-41-4.................................. Ethyl benzene
100-42-5.................................. Styrene*
100-44-7.................................. Benzyl chloride
100-51-6.................................. Benzyl alcohol
101-68-8.................................. 4,4-Methylenediphenyl diisocyanate*
103-71-9.................................. Phenyl isocyanate
105-60-2.................................. Caprolactam
106-44-5.................................. p-Cresol
106-50-3.................................. p-Phenylenediamine
106-88-7.................................. 1,2-Butylene oxide
106-93-4.................................. 1,2-Dibromoethane
106-96-7.................................. Propargyl bromide
106-97-8.................................. Butane*
106-99-0.................................. 1,3-Butadiene
107-05-1.................................. Allyl chloride
107-06-2.................................. 1,2-Dichloroethane
107-07-3.................................. Chloroethanol
75-05-8.................................. Acrylonitrile*
107-14-2.................................. Chloroacetonitrile*
107-16-4.................................. Formaldehyde cyanohydrin
107-19-7.................................. Propargyl alcohol
107-20-0.................................. Chloroacetaldehyde*
107-21-1.................................. Ethylene glycol
107-37-9.................................. Allyl trichlorosilane
107-72-2.................................. Amyltrichlorosilane
108-05-4.................................. *Vinyl acetate monomer
108-10-1.................................. 4-Methyl-2-pentanone
108-24-7.................................. Acetic anhydride*
108 31-6.................................. Maleic anhydride*
108-39-4.................................. m-Cresol
108-65-6.................................. Propylene glycol monomethyl ether acetate
108-67-8.................................. Mesitylene
108-90-7.................................. Chlorobenzene*
108-98-5.................................. Phenylmercaptan*
109-73-9.................................. n-Butylamine
109-77-3.................................. Malononitrile*
109-89-7.................................. Diethyl amine
109-90-0.................................. Ethyl isocyanate
109-99-9.................................. Tetrahydrofuran*
110-54-3.................................. Hexane*
110-57-6.................................. Trans-1,4-dichlorobutene
110-78-1.................................. n-Propyl isocyanate
110-82-7.................................. Cyclohexane*
110-86-1.................................. Pyridine
111-34-2.................................. Butyl vinyl ether
111-36-4.................................. n-Butyl isocyanate*
111-42-2.................................. Diethanolamine
111-44-4.................................. Dichloroethyl ether
111-48-8.................................. Thiodiglycol
111-69-3.................................. Adiponitrile
111-77-3.................................. Diethylene glycol monomethyl ether
111-88-6.................................. n-Octylmercaptan*
115-21-9.................................. Trichloroethyl silane
116-06-3.................................. Aldicarb*
116-14-3.................................. Tetrafluoroethylene
116-15-4.................................. Hexafluoropropylene
117-84-0.................................. Dioctyl phthalate
118-52-5.................................. 1,3-Dichloro-5,5- dimethylhydantoin
120-82-1.................................. 1,2,4-Trichlorobenzene
121-75-5.................................. Malathion
122-14-5.................................. Fenitrothion
123-31-9.................................. Hydroquinone
123-38-6.................................. Propionaldehyde*
123-86-4.................................. n-Butyl acetate*
124-40-3.................................. Dimethyl amine*
124-63-0.................................. Methanesulfonyl chloride
124-65-2.................................. Sodium cacodylate
129-00-0.................................. Pyrene
131-11-3.................................. Dimethyl phthalate
140-88-5.................................. Ethyl acrylate*
141-32-2.................................. Butylacrylate*
141-43-5.................................. Monoethanolamine
141-59-3.................................. t-Octyl mercaptan
141-66-2.................................. Dicrotophos
141-78-6.................................. Ethyl acetate*
143-33-9.................................. Sodium cyanide*
144-62-7.................................. Oxalic acid
149-74-6.................................. Dichloromethylphenyl silane
150-76-5.................................. p-Methoxyphenol
151-38-2.................................. Methoxyethylmercury acetate
207-08-9.................................. Benzo(k)fluoranthene
218-01-9.................................. Chrysene
287-92-3.................................. Cyclopentane
297-78-9.................................. Isobenzan
298-00-0.................................. Methyl parathion*
298-02-2.................................. Phorate*
298-04-4.................................. Disulfoton*
300-62-9.................................. Amphetamine
333-41-5.................................. Diazinon
334-88-3.................................. Diazomethane*
353-50-4.................................. Carbonyl fluoride*
354-32-5.................................. Trifluoroacetyl chloride
371-62-0.................................. Ethylene fluorohydrin
382-21-8.................................. Perfluoroisobutylenene
453-18-9.................................. Methyl fluoroacetate*
460-19-5.................................. Cyanogen*
463-51-4.................................. Ketene*
463-58-1.................................. Carbonyl sulfide*
463-71-8.................................. Thiophosgene
503-38-8.................................. Diphosgene
506-68-3.................................. Cyanogen bromide*
506-78-5.................................. Cyanogen iodide
506-96-7.................................. Acetyl bromide
534-52-1.................................. 4,6-Dinitro-o-cresol
538-07-8.................................. Bis(2-chloroethyl)ethylamine
541-25-3.................................. Lewisite
541-41-3.................................. Ethyl chloroformate*
542-88-1.................................. bis-Chloromethyl ether*
543-27-1.................................. i-Butyl chloroformate
555-77-1.................................. Tris(2-chloroethyl)amine (N- Mustard)
556-61-6.................................. Methyl isothiocyanate
556-64-9.................................. Methyl thiocyanate*
563-12-2.................................. Ethion
578-94-9.................................. Adamsite
592-34-7.................................. n-Butyl chloroformate
593-53-3.................................. Methyl fluoride
593-89-5.................................. Methyl dichloroarsine
598-14-1.................................. Ethyl dichloroarsine
598-31-2.................................. Bromoacetone
622-44-6.................................. Phenyl carbylamine chloride
624-92-0.................................. Dimethyl disulfide*
625-55-8.................................. Isopropyl formate
627-44-1.................................. Diethyl mercury
640-19-7.................................. Fluoroacetamide
646-06-0.................................. Diulane
674-82-8.................................. Diketene*
675-14-9.................................. Cyanuric fluoride
676-83-5.................................. Methyl phosphonous dichloride
676-97-1.................................. Methyl phosphonic dichloride
681-84-5.................................. Tetamethoxysilane
684-16-2.................................. Hexafluoroacetone*
696-28-6.................................. Phenyl dichloroarsine
732-11-6.................................. Phosmet
757-58-4.................................. Hexaethyl tetraphosphate
813-78-5.................................. Dimethyl phosphate
919-86-8.................................. Demeton S-methyl
920-46-7.................................. Methacryloyl chloride
944-22-9.................................. Fonofos*
950-37-8.................................. Methidathion*
993-00-0.................................. Methyl chlorosilane*
993-13-5.................................. Methylphosphonic acid
993-43-1.................................. Ethylphosphonodithioicdichlo ride
999-81-5.................................. Clormequat chloride
1024-57-3................................. Heptachlor epoxide
1120-71-4................................. 1,3-Propane sultone
1303-28-2................................. Arsenic pentoxide
1306-02-1................................. Lewisite oxide
1314-84-7................................. Zinc phosphide
1319-77-3................................. Cresol*
1327-53-3................................. Arsenic trioxide*
1336-36-3................................. Polychlorinated biphenyl
1341-24-8................................. Chloroacetophenone*
1341-49-7................................. Ammonium bifluoride
1397-94-0................................. Antimycin A
1498-40-4................................. Ethylphosphonous dichloride
1498-51-7................................. Ethylphosphorodichloridate
1558-25-4................................. Chloromethyl (trichloro) silane
1563-66-2................................. Carbofuran*
1582-09-8................................. Trifluralin
1609-86-5................................. t-Butyl isocyanate
1634-04-4................................. Methyl t-butyl ether*
1675-54-3................................. Bisphenol A diglycidyl ether
1737-93-5................................. 3,5-Dichloro-2,4,5- trifluoropyridine
1746-01-6................................. 2,3,7,8-Tetrachlorodibenzo-p- dioxin*
1832-54-8................................. Isopropyl methyl phosphonic acid
1873-29-6................................. Isobutyl isocyanate
1910-42-5................................. Paraquat dichloride*
2032-65-7................................. Methiocarb
2231-57-4................................. Thiocarbazide
2487-90-3................................. Trimethoxysilane
2524-03-0................................. Dimethyl phosphorochloridothioate
2696-92-6................................. Nitrosyl chloride*
2698-41-1................................. o-Chlorobenzylidene malononitrile*
2699-79-8................................. Sulfuryl fluoride*
2937-50-0................................. Allylchloroformate
2941-64-2................................. Ethyl chlorothioformate
3048-64-4................................. Vinyl norbornene
3173-53-3................................. Cyclohexyl isocyanate*
3282-30-2................................. Trimethylacetyl chloride
3689-24-5................................. Tetraethyl dithiopyrophosphate (Sulfotep)*
3691-35-8................................. Chlorophacinone
4098-71-9................................. Isophorone diisocyanate
4109-96-0................................. Dichlorosilane
4300-97-4................................. Chloropivaloyl chloride
4418-66-0................................. Phenol, 2,2'-thiobis(4- chloro-6-methyl-)
5332-73-0................................. 3-Methoxypropyl amine
5798-79-8................................. Bromobenzyl cyanide
6427-21-0................................. Methoxymethyl isocyanate
6581-06-2................................. 3-Quinuclidinyl benzilate
6923-22-4................................. Monocrotophos*
7439-92-1................................. Lead & compounds including lead phosphate*
7439-96-5................................. Manganese & compounds
7439-97-6................................. Mercury & compounds including methyl mercury*
7440-02-0................................. Nickel and compounds*
7440-38-2................................. Arsenic & compounds*
7440-39-3................................. Barium & compounds
7440-41-7................................. Beryllium & compounds*
7440-43-9................................. Cadmium & compounds*
7440-48-4................................. Cobalt & compounds
7440-50-8................................. Copper & compounds
7440-62-2................................. Vanadium & compounds
7440-66-6................................. Zinc & compounds
7446-18-6................................. Thallium sulfate*
7446-70-0................................. Aluminum chloride
7521-80-4................................. Butyltrichlorosilane
7550-45-0................................. Titanium tetrachloride*
7580-67-8................................. Lithium hydride
7616-94-6................................. Perchloryl fluoride
7631-89-2................................. Sodium arsenate
7647-19-0................................. Phosphorus pentafluoride*
7664-38-2................................. Phosphoric acid*
7705-07-9................................. Titanium chloride
7719-09-7................................. Thionyl chloride*
7722-84-1................................. Hydrogen peroxide (concentration greater than 52%)*
7723-14-0................................. Phosphorus
7727-15-3................................. Aluminum bromide
7738-94-5................................. Chromic acid
7782-65-2................................. Germane
7782-68-5................................. Iodic acid
7783-07-5................................. Hydrogen selenide*
7783-41-7................................. Oxygen difluoride*
7783-54-2................................. Nitrogen trifluoride*
7783-61-1................................. Silicon tetrafluoride*
7783-70-2................................. Antimony pentafluoride
7783-71-3................................. Tantalum V fluoride
7783-79-1................................. Selenium hexafluoride*
7783-80-4................................. Tellurium hexafluoride*
7783-82-6................................. Tungsten hexafluoride
7784-46-5................................. Sodium arsenite*
7786-34-7................................. Mevinphos*
7787-71-5................................. Bromine trifluoride*
7789-21-1................................. Fluorosulfonic acid
7789-30-2................................. Bromine pentafluoride*
7789-59-5................................. Phosphorus oxybromide
7789-69-7................................. Phosphorus pentabromide
7789-75-5................................. Calcium fluoride
7790-94-5................................. Chlorosulfonic acid*
7791-23-3................................. Selenium oxychloride
7791-25-5................................. Sulfuryl chloride*
7803-49-8................................. Hydroxylamine*
7803-52-3................................. Stibine (antimony hydride)*
7803-62-5................................. Silane*
8001-35-2................................. Camphechlor
8006-61-9................................. Gasoline*
10025-67-9................................ Disulfur dichloride
10025-73-7................................ Chromic chloride
10026-13-8................................ Phosphorus pentachloride
10028-15-6................................ Ozone*
10034-85-2................................ Hydrogen iodide*
10035-10-6................................ Hydrogen bromide*
10265-92-6................................ Methamidophos*
10294-33-4................................ Boron tribromide*
10544-72-6................................ Nitrogen tetroxide
10544-73-7................................ Nitrogen trioxide
10545-99-0................................ Sulfur dichloride*
11099-02-8................................ Nickel oxide*
12002-03-8................................ Copper acetoarsenite*
12108-13-3................................ Manganese, tricarbonyl methylcyclopentadienyl
13071-79-9................................ Terbufos*
13194-48-4................................ Ethoprophos
13470-08-1................................ Titanium III fluoride
13637-63-3................................ Chlorine pentafluoride*
13863-41-7................................ Bromine chloride*
16752-77-5................................ Methomyl*
17462-58-7................................ sec-Butyl Chloroformate
19624-22-7................................ Pentaborane*
20816-12-0................................ Osmium tetroxide*
20859-73-8................................ Aluminum phosphide*
22224-92-6................................ Fenamiphos
22967-92-6................................ Methyl mercury
23135-22-0................................ Oxamyl
23422-53-9................................ Formetanate hydrochloride
25321-14-6................................ Dinitrotoluene
25321-22-6................................ Dichlorobenzene
26419-73-8................................ Tirpate
27137-85-5................................ Trichloro (dichlorophenyl) silane
28772-56-7................................ Bromodiolone
30674-80-7................................ Methacryloyloxyethyl isocyanate
32315-10-9................................ Triphosgene

------------------------------------------------------------------------

*Indicates Higher Priority