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Registry of Toxic Effects of Chemical Substances (RTECS)

Nitrous acid, isobutyl ester

RTECS #

RA0805000

CAS #

542-56-3

Updated

September 201

Molecular Weight

103.14

Molecular Formula

C4H9NO2

Synonyms

Blackjack
Isobutyl nitrite
NCI-C61052
Nitrous acid, 2-methylpropyl ester (9CI)

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
DNA Damagelung/rat7.8 µmol/L/20HMUREAV 605,94,2006
DNA Damagelung/human3.9 µmol/L/20HMUREAV 605,94,2006
DNA Damageoral/rat606 mg/kgMUREAV 605,94,2006
mutation in mammalian somatic cellslymphocyte/mouse75900 nmol/LEMMUEG 14,115,1989
mutation in microorganisms/Salmonella typhimurium28 mg/L/2H (-enzymatic activation step)MUREAV 578,210,2005
mutation in microorganisms/Salmonella typhimurium500 mg/L/2H (+enzymatic activation step)MUREAV 578,210,2005
mutation in microorganisms/Salmonella typhimurium1 mg/plate (+enzymatic activation step)BSIBAC 56,816,1980
mutation in microorganisms/Salmonella typhimurium333 µg/plate (-enzymatic activation step)NTPTB* APR1982

Tumorigenic Data and References

Route/OrganismDoseEffectReference
inhalation/mouse lowest published toxic concentration: 150 ppm/6H/2Y- intermittentTumorigenic: Neoplastic by RTECS criteria

Lung, Thorax, or Respiration: Tumors
NTPTR* NTP-TR-448,1996
inhalation/mouse lowest published toxic concentration: 9270 mg/kg/103W- intermittentTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Lung, Thorax, or Respiration: Tumors
NTIS** PB97-120232
inhalation/rat lowest published toxic concentration: 150 ppm/6H/2Y- intermittentTumorigenic: Carcinogenic by RTECS criteria

Lung, Thorax, or Respiration: Tumors
NTPTR* NTP-TR-448,1996
inhalation/rat lowest published toxic concentration: 4635 mg/kg/103W- intermittentTumorigenic: Carcinogenic by RTECS criteria

Lung, Thorax, or Respiration: Tumors
NTIS** PB97-120232
inhalation/rat lowest published toxic concentration: 3862.5 mg/kg/103W- intermittentTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Lung, Thorax, or Respiration: Tumors
NTIS** PB97-120232

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/mouse lethal concentration (50 percent kill): 1033 ppm/1HBehavioral: Change in motor activity (specific assay)

Lung, Thorax, or Respiration: Cyanosis

Kidney, Ureter, and Bladder: Urine volume increased
FAATDF 1,448,1981
inhalation/mouse lowest published toxic concentration: 900 ppm/45MEndocrine: Other changesTOLED5 116,151,2000
inhalation/rat lethal concentration (50 percent kill): 777 ppm/4HBehavioral: Altered sleep time (including change in righting reflex)

Behavioral: Excitement

Lung, Thorax, or Respiration: Cyanosis
FAATDF 8,101,1987
intraperitoneal/mouse lethal dose (50 percent kill): 184 mg/kgLiver: Other changesRCOCB8 26,75,1979
oral/man lowest published toxic dose: 120 mg/kgBlood: Methemoglobinemia- Carboxhemoglobinemia

Vascular: BP lowering not characterized in autonomic section

Cardiac: Change in rate
AIMEAS 92,637,1980
oral/mouse lethal dose (50 percent kill): 205 mg/kgLiver: Other changes

Blood: Methemoglobinemia- Carboxhemoglobinemia
RCSADO 3,233,1982
oral/rat lethal dose (50 percent kill): 410 mg/kgBehavioral: General anestheticFEPRA7 41,1583,1982

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
inhalation/mouse lowest published toxic concentration: 400 ppm/7H/60D- intermittentLiver: Changes in liver weight

Kidney, Ureter, and Bladder: Changes in bladder weight

Endocrine: Changes in spleen weight
JJATDK 5,134,1985
inhalation/mouse lowest published toxic concentration: 800 ppm/6H/2W- intermittentLung, Thorax, or Respiration: Changes in lung weight

Nutritional and Gross Metabolic: Weight loss or decreased weight gain

Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field
FAATDF 19,169,1992
inhalation/mouse lowest published toxic concentration: 300 ppm/6H/14W- intermittentLung, Thorax, or Respiration: Structural or functional change in trachea or bronchi

Blood: Changes in erythrocyte (RBC) count

Blood: Changes in leukocyte (WBC) count
FAATDF 19,169,1992
inhalation/mouse lowest published toxic concentration: 300 ppm/6.5H/18W- intermittentLiver: Changes in liver weight

Blood: Methemoglobinemia- Carboxhemoglobinemia

Blood: Changes in leukocyte (WBC) count
JTEHD6 15,823,1985
inhalation/mouse lowest published toxic concentration: 900 ppm/5D- intermittentImmunological Including Allergic: Decreased immune response

Biochemical: Metabolism (intermediary): Other proteins

Biochemical: Metabolism (intermediary): Effect on inflammation or mediation of inflammation
TOLED5 152,47,2004
inhalation/rat lowest published toxic concentration: 600 ppm/6H/2W- intermittentLung, Thorax, or Respiration: Other changes

Liver: Other changes

Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field
FAATDF 19,169,1992
inhalation/rat lowest published toxic concentration: 150 ppm/6H/13W- intermittentOlfaction: Other olfaction effects

Blood: Methemoglobinemia- Carboxhemoglobinemia

Blood: Changes in erythrocyte (RBC) count
FAATDF 19,169,1992

Reviews

OrganizationStandardReference
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-ceiling concentration 1 ppm (inhal, vapor)DTLVS* TLV/BEI,2013
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-Confirmed animal carcinogenDTLVS* TLV/BEI,2013
TOXICOLOGY REVIEWENTOX* -,231,2005
TOXICOLOGY REVIEWMUREAV 584,1,2005
TOXICOLOGY REVIEWMUREAV 659,202,2008
TOXICOLOGY REVIEWHUTOX* -,577,1996
TOXICOLOGY REVIEWNCLNA* 16,503,1998

Standards and Regulations

OrganizationStandardReference
Occupational Exposure Limit-BELGIUMshort term exposure limit 1 ppm (4.3 mg/m3) (vapor, aer), Carcinogen, MAR2002

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Occupational Exposure Survey 1983Hazard Code X4720; Number of Industries 1; Total Number of Facilities 13; Number of Occupations 4; Total Number of Employees Exposed 290; Total Number of Female Employees Exposed 13

Status in Federal Agencies

OrganizationReference
EPA TSCA Section 8(b) CHEMICAL INVENTORY
NCI Carcinogenesis Studies (inhal);clear evidence:rat
NCI Carcinogenesis Studies (inhal);equivocal evidence:mouse
NTP Carcinogenesis studies (inhalation);some evidence:mouse NTPTR* NTP-TR-448,1996
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