Registry of Toxic Effects of Chemical Substances (RTECS)

Hydrocyanic acid

RTECS #

MW6825000

CAS #

74-90-8

Updated

September 201

Molecular Weight

27.03

Molecular Formula

CHN

Synonyms

Acide cyanhydrique (French)
Acido cianidrico (Italian)
Aero Liquid HCN
Blausaeure (German)
Blauwzuur (Dutch)
Carbon hydride nitride (chn)
Cyaanwaterstof (Dutch)
Cyanwasserstoff (German)
Cyclon
Cyclone B
Cyjanowodor (Polish)
Evercyn
Formic anammonide
Formonitrile
Hydrogen cyanide
Hydrogen cyanide (ACGIH:OSHA)
Prussic acid
Prussic acid, unstabilized
RCRA waste number P063
Zaclondiscoids

Acute Toxicity Data and References

Route/Organism	Dose	Effect	Reference
inhalation/cat	Lowest published lethal concentration: 550 mg/m³		VCVN1* -,334,1988
inhalation/human	lowest published toxic concentration: 20 mg/m³	Gastrointestinal: Nausea or vomiting Cardiac: Pulse rate decreased with fall in BP	VCVN1* -,334,1988
inhalation/human	Lowest published lethal concentration: 100 mg/m³/1H	Brain and Coverings: Changes in circulation Liver: Other changes Kidney, Ureter, and Bladder: Other changes	VCVN1* -,334,1988
inhalation/human	Lowest published lethal concentration: 120 mg/m³/30M	Brain and Coverings: Changes in circulation Liver: Other changes Kidney, Ureter, and Bladder: Other changes	VCVN1* -,334,1988
inhalation/human	Lowest published lethal concentration: 200 mg/m³/10M	Brain and Coverings: Changes in circulation Liver: Other changes Kidney, Ureter, and Bladder: Other changes	VCVN1* -,334,1988
inhalation/human	lowest published toxic concentration: 5 mg/m³	Behavioral: Headache	TOVEFN (2),39,2001
inhalation/human	lowest published toxic concentration: 20 mg/m³	Cardiac: Pulse rate increased without fall in BP Gastrointestinal: Nausea or vomiting	TOVEFN (2),39,2001
inhalation/human	Lowest published lethal concentration: 100 mg/m³/1H		TOVEFN (2),39,2001
inhalation/human	Lowest published lethal concentration: 120 mg/m³/30M		TOVEFN (2),39,2001
inhalation/human	Lowest published lethal concentration: 200 mg/m³/10M		TOVEFN (2),39,2001
inhalation/human	Lowest published lethal concentration: 200 mg/m³/10M	Behavioral: General anesthetic Lung, Thorax, or Respiration: Dyspnea Gastrointestinal: Nausea or vomiting	WHOTAC -,30,1970
inhalation/mammal (species unspecified)	Lowest published lethal concentration: 200 ppm/5M		AEPPAE 138,65,1928
inhalation/mammal (species unspecified)	Lowest published lethal concentration: 36 ppm/2H		TABIA2 3,231,1933
inhalation/man	Lowest published lethal concentration: 400 mg/m³/2M		85GMAT -,75,1982
inhalation/man	lowest published toxic concentration: 500 mg/m³/3M-continuous	Eye: Mydriasis (pupilliary dilation) Behavioral: Coma Lung, Thorax, or Respiration: Respiratory depression	HUTODJ 3,57,1984
inhalation/monkey	lowest published toxic concentration: 17 ppm/10M	Brain and Coverings: Other degenerative changes Lung, Thorax, or Respiration: Respiratory stimulation	TOXID9 72,159,2003
inhalation/monkey	lowest published toxic concentration: 10 ppm/30M	Brain and Coverings: Other degenerative changes Lung, Thorax, or Respiration: Respiratory stimulation	TOXID9 72,159,2003
inhalation/monkey	lowest published toxic concentration: 7.1 ppm/1H	Brain and Coverings: Other degenerative changes Lung, Thorax, or Respiration: Respiratory stimulation	TOXID9 72,159,2003
inhalation/monkey	lowest published toxic concentration: 3.5 ppm/4H	Brain and Coverings: Other degenerative changes Lung, Thorax, or Respiration: Respiratory stimulation	TOXID9 72,159,2003
inhalation/monkey	lowest published toxic concentration: 2.5 ppm/8H	Brain and Coverings: Other degenerative changes Lung, Thorax, or Respiration: Respiratory stimulation	TOXID9 72,159,2003
inhalation/mouse	lethal concentration (50 percent kill): 177 ppm/29M		ENTOX* -,698,2005
inhalation/mouse	lethal concentration (50 percent kill): 48.65 mg/m³/2H		TPKVAL 9,7,1967
inhalation/mouse	lethal concentration (50 percent kill): 45.3 ppm/2H		TPKVAL 9,7,1967
inhalation/mouse	lethal concentration (50 percent kill): 323 ppm/5M		TXAPA9 42,417,1977
inhalation/rabbit	lethal concentration (50 percent kill): 208 mg/m³/35M	Brain and Coverings: Other degenerative changes Cardiac: Other changes Blood: Other changes	TSUJDP 13,263,1994
inhalation/rat	lethal concentration (50 percent kill): 150 ppm/30M		ENTOX* -,639,2005
inhalation/rat	Lowest published lethal concentration: 138 ppm/15M		TOXID9 72,159,2003
inhalation/rat	Lowest published lethal concentration: 127 ppm/30M		TOXID9 72,159,2003
inhalation/rat	Lowest published lethal concentration: 88 ppm/1H		TOXID9 72,159,2003
inhalation/rat	lowest published toxic concentration: 10 ppm	Ear: Change in acuity Ear: Change in cochlear structure or function	TOSCF2 66,131,2002
intramuscular/mouse	lethal dose (50 percent kill): 2700 µg/kg		BJPCAL 23,455,1964
intramuscular/pigeon	lowest published lethal dose: 1500 µg/kg		FDWU** -,-,1931
intramuscular/rabbit	lethal dose (50 percent kill): 486 µg/kg		JACTDZ 1(3),120,1982
intraperitoneal/mouse	lethal dose (50 percent kill): 2990 µg/kg		BJPCAL 23,455,1964
intraperitoneal/rabbit	lethal dose (50 percent kill): 1570 µg/kg		BJPCAL 23,455,1964
intravenous/cat	lethal dose (50 percent kill): 810 µg/kg		NTIS** AD-A028-501
intravenous/Dog	lethal dose (50 percent kill): 1340 µg/kg		NTIS** AD-A028-501
intravenous/domestic animal	lethal dose (50 percent kill): 660 µg/kg		NTIS** PB158-508
intravenous/guinea pig	lethal dose (50 percent kill): 1430 µg/kg		NTIS** AD-A028-501
intravenous/man	lowest published toxic dose: 55 µg/kg	Lung, Thorax, or Respiration: Respiratory stimulation	NTIS** PB158-508
intravenous/monkey	lethal dose (50 percent kill): 1300 µg/kg		NTIS** AD-A028-501
intravenous/mouse	lethal dose (50 percent kill): 990 µg/kg		NTIS** AD-A028-501
intravenous/rabbit	lethal dose (50 percent kill): 660 µg/kg		NTIS** AD-A028-501
intravenous/rat	lethal dose (50 percent kill): 810 µg/kg		NTIS** AD-A028-501
ocular/rabbit	lethal dose (50 percent kill): 1040 µg/kg	Eye: Other eye effects Behavioral: Ataxia Lung, Thorax, or Respiration: Respiratory stimulation	JTOTDO 2,119,1983
oral/Dog	lowest published lethal dose: 4 mg/kg		HBAMAK 4,1340,1935
oral/domestic bird	lowest published lethal dose: 600 µg/kg		FDWU** -,-,1931
oral/duck	lowest published lethal dose: 3280 µg/kg		FDWU** -,-,1931
oral/human	lowest published lethal dose: 570 µg/kg		PCOC** -,596,1966
oral/mouse	lethal dose (50 percent kill): 3700 µg/kg		APFRAD 19,740,1961
oral/pig	lowest published lethal dose: 2 mg/kg		AEHLAU 22,496,1971
oral/pigeon	lowest published lethal dose: 14 mg/kg		FDWU** -,-,1931
oral/rabbit	lowest published lethal dose: 4 mg/kg		HBAMAK 4,1340,1935
oral/wild bird	lowest published lethal dose: 7500 µg/kg		FDWU** -,-,1931
subcutaneous/cat	lowest published lethal dose: 1100 µg/kg		HBAMAK 4,1340,1935
subcutaneous/Dog	lowest published lethal dose: 1700 µg/kg		HBAMAK 4,1340,1935
subcutaneous/domestic bird	lowest published lethal dose: 100 µg/kg		HBAMAK 4,1340,1935
subcutaneous/frog	lowest published lethal dose: 60 mg/kg		HBAMAK 4,1340,1935
subcutaneous/guinea pig	lowest published lethal dose: 100 µg/kg		HBAMAK 4,1340,1935
subcutaneous/human	lowest published lethal dose: 1 mg/kg		SCJUAD 3(4),33,1967
subcutaneous/mouse	lowest published lethal dose: 3 mg/kg		HBAMAK 4,1340,1935
subcutaneous/pigeon	lowest published lethal dose: 2150 µg/kg		FDWU** -,-,1931
subcutaneous/rabbit	lethal dose (50 percent kill): 2500 µg/kg		BJPCAL 23,455,1964
subcutaneous/wild bird	lowest published lethal dose: 100 µg/kg		FDWU** -,-,1931
unreported route/man	lowest published lethal dose: 1471 µg/kg		85DCAI 2,73,1970

Other Multiple Dose Data and References

Route/Organism	Dose	Effect	Reference
oral/domestic animal	lowest published toxic dose: 75 mg/kg/30D- continuous	Brain and Coverings: Other degenerative changes Endocrine: Other changes Nutritional and Gross Metabolic: Changes in: Cl	JAPTO* 28,356,2008
oral/domestic animal	lowest published toxic dose: 10 mg/kg/4D- continuous	Behavioral: Alteration of classical conditioning	JAPTO* 28,356,2008
oral/domestic animal	lowest published toxic dose: 15 mg/kg/6D- continuous	Behavioral: Convulsions or effect on seizure threshold	JAPTO* 28,356,2008

Reviews

Organization	Standard	Reference
American Conference of Governmental Industrial Hygienists (ACGIH)	Threshold Limit Value-ceiling concentration 4.7 ppm (skin)	DTLVS* TLV/BEI,2013
TOXICOLOGY REVIEW		EVHPAZ 11,163,1975
TOXICOLOGY REVIEW		FNSCA6 2,67,1973
TOXICOLOGY REVIEW		JOCMA7 1,281,1959
TOXICOLOGY REVIEW		TOLED5 134,3,2002
TOXICOLOGY REVIEW		CPEMM* 3,239,2002
TOXICOLOGY REVIEW		TXCYAC 214,221,2005
TOXICOLOGY REVIEW		ENTOX* -,639,2005
TOXICOLOGY REVIEW		ENTOX* -,698,2005
TOXICOLOGY REVIEW		REPTED 23,428,2007
TOXICOLOGY REVIEW		HUTOX* -,661,1996
TOXICOLOGY REVIEW		MUREAV 636,144,2007
TOXICOLOGY REVIEW		CCACL* 21,691,2005
TOXICOLOGY REVIEW		NEUCL* 15,711,1997
TOXICOLOGY REVIEW		PRESR* 7,123,2006
TOXICOLOGY REVIEW		NTAPM* -,629,1995
TOXICOLOGY REVIEW		MUREAV 717,46,2011

Standards and Regulations

Organization	Standard	Reference
Occupational Exposure Limit IN ARGENTINA, BULGARIA, COLOMBIA, JORDAN check ACGIH TLV;
Occupational Exposure Limit IN SINGAPORE, VIETNAM check ACGIH TLV
Occupational Exposure Limit-ARAB Republic of Egypt	time-weighted average 10 ppm (10 mg/m³), JAN1993
Occupational Exposure Limit-AUSTRALIA	ceiling concentration 10 ppm (11 mg/m³), JUL2008
Occupational Exposure Limit-AUSTRALIA	time-weighted average 5 mg(CN)/m³, JUL2008
Occupational Exposure Limit-AUSTRIA	MAK-TMW 10 ppm (11 mg/m³);KZW 40 ppm (44 mg/m³), skin, 2007
Occupational Exposure Limit-BELGIUM	short term exposure limit 4.7 ppm (5 mg/m³), Skin, MAR2002
Occupational Exposure Limit-DENMARK	time-weighted average 5 ppm (5 mg/m³), skin, MAY2011
Occupational Exposure Limit-FINLAND	time-weighted average 1 mg/m³, short term exposure limit 5 mg/m³, skin, NOV2011
Occupational Exposure Limit-FRANCE	VME 2 ppm (2 mg/m³), VLE 10 ppm (10 mg/m³), FEB2006
Occupational Exposure Limit-GERMANY	MAK 1.9 ppm (2.1 mg/m³), 2011
Occupational Exposure Limit-GERMANY	MAK 2 mg(CN)/m³, inhal, 2011
Occupational Exposure Limit-HUNGARY	time-weighted average 11 mg/m³, short term exposure limit 44 mg/m³, Skin, SEP2000
Occupational Exposure Limit-HUNGARY	time-weighted average 5 mg(CN)/m³, short term exposure limit 20 mg(CN)/m³, Skin, SEP2000
Occupational Exposure Limit-ICELAND	time-weighted average 5 ppm (5 mg/m³), skin, NOV2011
Occupational Exposure Limit-JAPAN	Occupational Exposure Limit 5 ppm (5.5 mg/m³), skin, MAY2012
Occupational Exposure Limit-KOREA	ceiling concentration 10 ppm (11 mg/m³), skin, 2006
Occupational Exposure Limit-MEXICO	peak 9.4 ppm (10 mg/m³), 2004
Occupational Exposure Limit-MEXICO	time-weighted average 5 mg(CN)/m³, 2004
Occupational Exposure Limit-NEW ZEALAND	ceiling concentration 10 ppm (11 mg/m³), skin, JAN2002
Occupational Exposure Limit-NORWAY	time-weighted average 5 ppm (5 mg/m³), JAN1999
Occupational Exposure Limit-PERU	short term exposure limit 4.7 ppm (5 mg/m³), JUL2005
Occupational Exposure Limit-POLAND	MAC(time-weighted average) 0.3 mg/m³, CEILING 10 mg/m³, JAN1999
Occupational Exposure Limit-RUSSIA	short term exposure limit 0.3 mg/m³, Skin, JUN2003
Occupational Exposure Limit-SWITZERLAND	MAK-week 1.9 ppm (2.1 mg/m³), KZG-week 3.8 ppm (4.2 mg/m³), skin, JAN2011
Occupational Exposure Limit-THAILAND	time-weighted average 10 ppm (11 mg/m³), JAN1993
Occupational Exposure Limit-THE NETHERLANDS	MAC-C 11 mg/m³, Skin, 2003
Occupational Exposure Limit-THE PHILIPPINES	time-weighted average 10 ppm (11 mg/m³), Skin, JAN1993
Occupational Exposure Limit-TURKEY	time-weighted average 10 ppm (11 mg/m³), Skin, JAN1993
Occupational Exposure Limit-UNITED KINGDOM	short term exposure limit 10 ppm (11 mg/m³), skin, OCT2007
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)	8H time-weighted average 10 ppm (11 mg/m³) (skin)	CFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Federal Contractors)	8H time-weighted average 10 ppm (11 mg/m³) (skin)	CFRGBR 41,50-204.50,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (General Industry)	8H time-weighted average 10 ppm (11 mg/m³) (skin)	CFRGBR 29,1910.1000,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)	8H time-weighted average 10 ppm (11 mg/m³) (skin)	CFRGBR 29,1915.1000,1993

NIOSH Documentation and Surveillance

Organization	Standard	Reference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO HYDROGEN CYANIDE-air	short term exposure limit 4.7 ppm (Sk)	NIOSH* DHHS #92-100,1992
National Occupational Exposure Survey 1983	Hazard Code 38530; Number of Industries 13; Total Number of Facilities 91; Number of Occupations 57; Total Number of Employees Exposed 3994; Total Number of Female Employees Exposed 254
National Occupational Hazard Survey 1974	Hazard Code 38530; Number of Industries 14; Total Number of Facilities 461; Number of Occupations 17; Total Number of Employees Exposed 2137

Status in Federal Agencies

Organization	Reference
EPA TSCA Section 8(b) CHEMICAL INVENTORY
EPA TSCA Section 8(d) unpublished health/safety studies
EPA TSCA Section 8(e) Risk Notification, 8EHQ-0892-9215
EPA TSCA TEST SUBMISSION (TSCATS) DATA BASE, JANUARY 2001
NIOSH Analytical Method, 1994: Cyanides (aerosol and gas), 7904
NIOSH Analytical Method, 1994: Hydrogen cyanide, 6010
On EPA IRIS database

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Page last reviewed:March 7, 2014
Page last updated:February 6, 2017
Content source:
- National Institute for Occupational Safety and Health (NIOSH) Education and Information Division

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