List of highly toxic gases

==Definition==
*Toxic: A chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats weighing between 200 and 300 grams each.
*NFPA 704: Materials that, under emergency conditions, can cause serious or permanent injury are given a Health Hazard rating of 3. Their acute inhalation toxicity corresponds to those vapors or gases having LC50 values greater than 1,000 ppm but less than or equal to 3,000 ppm. Materials that, under emergency conditions, can be lethal are given a Health Hazard rating of 4. Their acute inhalation toxicity corresponds to those vapors or gases having LC50 values less than or equal to 1,000 ppm.
==List==
Chemical name 	Chemical formula	CAS number	NIOSH IDLH in ppm 	LC50 Model	LC50 toxicity in ppmunless noted as occupational exposure limits. ACGIH Threshold Limit Values are listed with documentation date.ACGIH Threshold Limit Values for Chemical Substances and Physical Agents, 2009, ISBN 978-1-882417-95-7.	Odor warning property	NFPA 704 Health Rating
Arsenic pentafluoride 	AsF5 	7784-36-3 	 	Rat 	20 	inadequate 	4
Arsine 	AsH3 	7784-42-1 	3 	Rat 	20; ACGIH (2006) TWA-TLV 0.005ppm 	 	4
Bis(trifluoromethyl)peroxide 	C2F6O2 	927-84-4 	10 	Rat 	 	 	
Boron tribromide 	BBr3 	10294-33-4	50 	Rat 	380; ACGIH (1990) Ceiling limit 1ppm 	 	3
Boron trichloride 	BCl3 	10294-34-5	25 	Rat 	2541 	 	4
Boron trifluoride 	BF3 	7637-07-2 	25 	 	OSHA, ACGIH (1962) 1ppm ceiling 	 	4
Bromine 	2 	7726-95-6 	3 	 	ACGIH (1991) Short-Term Exposure Limit STEL-TLV 0.2ppm 	 	3
Bromine chloride 	BrCl 	13863-41-7	 	Rat 	290 	 	
Bromomethane 	CH3Br 	74-83-9 	 	Rat 	811.14 	 	3
Carbon monoxide 	CO 	630-08-0 	1,200 (moderately toxic)	 	ACGIH (1989) TWA TLV 25ppm; NIOSH 35ppm; NIOSH 200ppm Ceiling limit 	 	4
Chlorine 	2 	7782-50-5 	10 	 	ACGIH (1986) STEL-TLV 1ppm 	Odor threshold 1ppm 	
Chlorine pentafluoride 	ClF5 	13637-63-3	 	 	 	 	
Chlorine trifluoride 	ClF3 	7790-91-2 	 	 	ACGIH (1979) Ceiling limit 0.1ppm 	inadequate 	4
Chlorofluorocarbons 	 	 	 	 	 	 	
Chloropicrin 	CCl3NO2 	76-06-2 	 	 	ACGIH (1990) TWA-TLV 0.1ppm 	 	
Cyanogen 	C2N2 	460-19-5 	 	Rat 	350; ACGIH (1966) TWA-TLV 10ppm 	inadequate 	4
Cyanogen chloride 	CNCl 	506-77-4 	 	Rat 	1.2 mg/l/h; ACGIH (1977) ceiling limit 0.3ppm 	inadequate 	4
Diazomethane 	CH2N2 	334-88-3 	2 	 	ACGIH (1970) TWA-TLV 0.2ppm 	 	
Diborane 	B2H6 	19287-45-7	 	Rat 	80; ACGIH (1990) TWA-TLV 0.1ppm 	inadequate 	4
Dichloroacetylene 	C2Cl2 	7572-29-4 	 	Mouse 	45.6 	 	
Dichlorosilane 	H2Cl2Si 	4109-96-0 	 	Rat 	314 	 	4
Fluorine 	2 	7782-41-4 	 	Rat 	185; ACGIH (1970) STEL-TLV 2ppm 	odor threshold 20ppb 	
Formaldehyde, gas 	CH2O 	50-00-0 	 	Rat 	0.66; ACGIH (1987) Ceiling limit 0.3ppm 	 	3
Germane 	GeH4 	7782-65-2 	 	Rat 	622 	inadequate 	4
Hexaethyl tetraphosphate 	(C2H5O)6P4O7 	 	 	 	 	 	
Hydrogen azide 	HN3 	7782-79-8 	 	 	 	 	
Hydrogen cyanide 	HCN 	74-90-8 	 	Rat 	40; ACGIH (1991) ceiling limit 4.7ppm 	inadequate 	4
Hydrogen selenide 	H2Se 	7783-07-5 	1 	Rat 	2; ACGIH (1990) TWA-TLV 0.05ppm 	inadequate 	4
Hydrogen sulfide 	 	7783-06-4 	100 	Rat 	712; ACGIH (1990) STEL-TLV 15ppm 	 	4
Hydrogen telluride 	H2Te 	7783-09-7 	 	 	 	 	
Nickel tetracarbonyl 	Ni(CO)4 	13463-39-3	 	 	ACGIH (1980) TWA-TLV 0.05ppm 	inadequate 	4
Nitrogen dioxide 	 	10102-44-0	 	 	 	odor threshold 4 ppm 	
Osmium tetroxide 	OsO4 	20816-12-0	 	Rat 	 	 	
Oxygen difluoride 	OF2 	7783-41-7 	 	Rat 	2.6; ACGIH (1983) ceiling limit 0.05ppm 	 	
Perchloryl fluoride 	ClFO3 	7616-94-6 	 	Rat 	770; ACGIH (1962) STEL-TLV 6ppm 	 	
Perfluoroisobutylene 	C4F8 	382-21-8 	 	Rat 	1.2 	 	
Phosgene 	CCl2O 	75-44-5 	 	Rat 	5; ACGIH (1992) TWA-TLV 0.1ppm 	inadequate 	4
Phosphine 	PH3 	7803-51-2 	50 	 	NIOSH 0.3ppm time weighted average; ACGIH (1992) STEL-TLV 1ppm 	inadequate 	4
Phosphorus pentafluoride 	PF5 	7647-19-0 	 	Rat 	260 	 	
Selenium hexafluoride 	SeF6 	7783-79-1 	2 	Rat 	50; ACGIH (1992) TWA-TLV 0.05ppm 	 	
Silicon tetrachloride 	SiCl4 	10026-04-7	 	Rat 	750 	 	
Silicon tetrafluoride 	SiF4 	7783-61-1 	 	Rat 	450 	 	
Stibine 	H3Sb 	7803-52-3 	5 	Rat 	20 	 	4
Disulfur decafluoride 	S2F10 	5714-22-7 	1 	 	ACGIH (1962) ceiling limit 0.01ppm 	 	4
Sulfur tetrafluoride 	SF4 	7783-60-0 	 	Rat 	40; ACGIH (1992) ceiling limit 0.1ppm 	 	3
Tellurium hexafluoride 	TeF6 	7783-80-4 	 	Rat 	25; ACGIH (1992) TWA-TLV 0.02ppm 	 	
Tetraethyl pyrophosphate 	C8H20O7P2 	 	 	 	ACGIH (2006) TWA-TLV 0.01 mg/cubic meter 	 	
Tetraethyl dithiopyrophosphate	C8H20O5P2S2 	 	 	 	 	 	
Trifluoroacetyl chloride 	C2ClF3O 	354-32-5 	 	Rat 	1000 	 	
Tungsten hexafluoride 	WF6 	7783-82-6 	 	Rat 	217 	inadequate 	
== Notes ==
==See also==
* List of Schedule 1 substances (CWC)
* List of extremely hazardous substances
==References==
==Sources==
*Principles for the Safe Handling and Distribution of Highly Toxic Gases and Mixtures Asia Industrial Gases Association, 2006
Category:Air Pollution