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Registry of Toxic Effects of Chemical Substances (RTECS)

Isoprene

RTECS #

NT4037000

CAS #

78-79-5; 78006-92-5

Updated

June 2017

Molecular Weight

68.13

Molecular Formula

C5H8

Synonyms

1,3-Butadiene, 2-methyl-
2-Methyl-1,3-butadiene
2-Methylbutadiene
beta-Methylbivinyl
Isopentadiene
NSC 9237

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
DNA Damageinhalation/mouse700 ppm/26W- intermittentCBINA8 135-136,373,2001
DNA Damageleukocyte/human5 mmol/L/2H (+enzymatic activation step)MUREAV 629,7,2007
micronucleus testinhalation/mouse438 ppm/6H/12D-continuousMUTAEX 3,141,1988
micronucleus testinhalation/mouse438 ppm/12D- intermittentHPV159 -,-,2000
sister chromatid exchangeinhalation/mouse438 ppm/6H/12D-continuousMUTAEX 3,141,1988
sister chromatid exchangeinhalation/mouse438 ppm/12D- intermittentHPV159 -,-,2000

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
inhalation/mouse 280 ppm (6-17D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)NTIS** #DE89008095/XAD
inhalation/rat 7000 ppm (6-19D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal systemNTIS** #DE89008095/XAD
inhalation/mouse 7000 ppm (6-17D pregnant)Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)

Reproductive: Specific developmental abnormalities: Musculoskeletal system

Reproductive: Specific developmental abnormalities: Urogenital system
NTIS** #DE89008095/XAD

Tumorigenic Data and References

Route/OrganismDoseEffectReference
inhalation/mouse lowest published toxic concentration: 7000 ppm/6H/26W- intermittentTumorigenic: Carcinogenic by RTECS criteria

Lung, Thorax, or Respiration: Tumors

Liver: Tumors
CNREA8 54,5333,1994
inhalation/mouse lowest published toxic concentration: 700 ppm/6H/26W - intermittentTumorigenic: Neoplastic by RTECS criteria

Gastrointestinal: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
CBINA8 135-136,373,2001
inhalation/mouse lowest published toxic concentration: 70 ppm/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Skin and Appendages: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 140 ppm/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Liver: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 280 ppm/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Gastrointestinal: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 700 ppm/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Lung, Thorax, or Respiration: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 70 ppm/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Vascular: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/rat lowest published toxic concentration: 220 ppm/6H/2Y- intermittentTumorigenic: Carcinogenic by RTECS criteria

Skin and Appendages: Tumors
NTPTR* NTP-TR-486,1999
inhalation/rat lowest published toxic concentration: 22050 mg/kg/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Kidney, Ureter, and Bladder: Kidney tumors

Reproductive: Tumorigenic effects: Testicular tumors
NTIS** PB2000-101651
inhalation/rat lowest published toxic concentration: 220500 mg/kg/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Skin and Appendages: Tumors
NTIS** PB2000-101651
inhalation/rat lowest published toxic concentration: 5775 mg/kg/105W- intermittentTumorigenic: Neoplastic by RTECS criteria

Skin and Appendages: Tumors
NTIS** PB2000-101651
inhalation/rat lowest published toxic concentration: 7000 ppm/2Y- intermittentTumorigenic: Neoplastic by RTECS criteria

Reproductive: Tumorigenic effects: Testicular tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/rat lowest published toxic concentration: 7000 ppm/2Y- intermittentTumorigenic: Neoplastic by RTECS criteria

Kidney, Ureter, and Bladder: Kidney tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000
inhalation/rat lowest published toxic concentration: 7000 ppm/2Y- intermittentTumorigenic: Neoplastic by RTECS criteria

Skin and Appendages: Tumors

Tumorigenic: Increased incidence of tumors in susceptible strains
HPV159 -,-,2000

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/cat lowest published toxic concentration: 800 mg/m3Gastrointestinal: Changes in structure or function of salivary glandsVCVGH* -,65,1990
inhalation/cat lowest published toxic concentration: 0.8 gm/m3/2HSkin: After systemic exposure: Dermatitis, otherTPKVAL 6,18,1964
inhalation/cat lowest published toxic concentration: 0.4 gm/m3/2HEye: Conjunctiva irritationTPKVAL 6,18,1964
inhalation/human lowest published toxic concentration: 160 mg/m3/1MEye: Conjunctiva irritationVCVGH* -,66,1990
inhalation/mouse Lowest published lethal concentration: 140 gm/m3Behavioral: Alteration of classical conditioningTPKVAL 6,18,1964
inhalation/mouse lethal concentration (50 percent kill): 150 gm/m3/2HPeripheral Nerve and Sensation: Recording from peripheral motor nerveTPKVAL 6,18,1964
inhalation/mouse lowest published toxic concentration: 100 gm/m3/2HSkin: After systemic exposure: Dermatitis, otherTPKVAL 6,18,1964
inhalation/mouse lethal concentration (50 percent kill): 157000 mg/m3/4HHPV159 -,-,2000
inhalation/mouse lethal concentration (50 percent kill): 139 gm/m3/2HLung, Thorax, or Respiration: Other changesGTPZAB 9(1),36,1965
inhalation/mouse lethal concentration (50 percent kill): 130000 mg/m3/2HVCVGH* -,65,1990
inhalation/mouse lethal concentration (16 percent kill): 117000 mg/m3/2HVCVGH* -,65,1990
inhalation/mouse lethal concentration (84 percent kill): 212000 mg/m3/2HVCVGH* -,65,1990
inhalation/rabbit lowest published toxic concentration: 750 mg/m3/40MLung, Thorax, or Respiration: DyspneaVCVGH* -,66,1990
inhalation/rabbit lowest published toxic concentration: 300 mg/m3Behavioral: Alteration of classical conditioningVCVGH* -,66,1990
inhalation/rat lethal concentration (50 percent kill): 129000 mg/m3/4HVCVGH* -,65,1990
inhalation/rat lethal concentration (16 percent kill): 92000 mg/m3/4HVCVGH* -,65,1990
inhalation/rat lethal concentration (84 percent kill): 381000 mg/m3/4HVCVGH* -,65,1990
inhalation/rat lethal concentration (50 percent kill): 180 gm/m3/4HBehavioral: General anesthetic

Lung, Thorax, or Respiration: Respiratory depression
RPTOAN 31,162,1968
inhalation/rat lowest published toxic concentration: 0.4 gm/m3/2HBrain and Coverings: Changes in circulation

Behavioral: Convulsions or effect on seizure threshold

Cardiac: Other changes
TPKVAL 6,18,1964
oral/rat lowest published lethal dose: 4.5 gm/kgBehavioral: Somnolence (general depressed activity)

Lung, Thorax, or Respiration: Respiratory depression
VCVGH* -,66,1990
skin/rabbit lowest published toxic dose: 0.25 mL/kgSkin: After systemic exposure: Dermatitis, otherVCVGH* -,67,1990

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
inhalation/guinea pig lowest published toxic concentration: 3400 mg/m3/17W- intermittentBehavioral: Alteration of classical conditioning

Blood: Changes in leukocyte (WBC) count
GTPZAB 9(1),36,1965
inhalation/mouse lowest published toxic concentration: 438 ppm/2W- intermittentLiver: Changes in liver weight

Endocrine: Changes in thymus weight

Related to Chronic Data: Changes in testicular weight
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 700 ppm/13W- intermittentOlfaction: Other olfaction effects

Liver: Hepatitis (hepatocellular necrosis), diffuse

Blood: Macrocytosis
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 700 ppm/13W- intermittentReproductive: Paternal effects: Spermatogenesis (including genetic material, sperm morphology, motility, and count)

Reproductive: Paternal effects: Testes, epididymis, sperm duct
HPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 7000 ppm/13W- intermittentEndocrine: Effect on menstrual cycleHPV159 -,-,2000
inhalation/mouse lowest published toxic concentration: 3400 mg/m3/17W- intermittentBehavioral: Change in psychophysiological testsGTPZAB 9(1),36,1965
inhalation/mouse lowest published toxic concentration: 700 ppm/6H/13W- intermittentGastrointestinal: Other changesCNREA8 54,5333,1994
inhalation/mouse lowest published toxic concentration: 7000 ppm/14D- intermittentKidney, Ureter, and Bladder: Changes in kidney weight

Nutritional and Gross Metabolic: Weight loss or decreased weight gain
NTIS** #DE89008095/XAD
inhalation/mouse lowest published toxic concentration: 1400 ppm/14D- intermittentLiver: Changes in liver weightNTIS** #DE89008095/XAD
inhalation/rat lowest published toxic concentration: 0.3 gm/m3/61D- intermittentLiver: Liver function tests impairedTPKVAL 6,18,1964
inhalation/rat lowest published toxic concentration: 0.3 gm/m3/0.5Y- intermittentCardiac: Other changes

Lung, Thorax, or Respiration: Emphysema

Kidney, Ureter, and Bladder: Changes in tubules (including acute renal failure, acute tubular necrosis)
TPKVAL 6,18,1964
inhalation/rat lowest published toxic concentration: 3400 mg/m3/22W- intermittentBrain and Coverings: Changes in brain weight

Lung, Thorax, or Respiration: Changes in lung weight

Kidney, Ureter, and Bladder: Changes in kidney weight
GTPZAB 9(1),36,1965
inhalation/rat lowest published toxic concentration: 7000 ppm/14D- intermittentKidney, Ureter, and Bladder: Changes in kidney weightNTIS** #DE89008095/XAD
inhalation/rat lowest published toxic concentration: 7000 ppm/13W- intermittentReproductive: Paternal effects: Testes, epididymis, sperm ductHPV159 -,-,2000
intraperitoneal/mouse lowest published toxic dose: 14973.6 mg/kg/30D- intermittentReproductive: Maternal effects: OogenesisCRTOEC 8,963,1995
oral/rat lowest published toxic dose: 157 mg/kg/9W- continuousBehavioral: Alteration of classical conditioningGISAAA 24(6),8,1959

Reviews

OrganizationStandardReference
International Agency for Research on Cancer (IARC)Cancer Review:Animal Sufficient EvidenceIMEMDT 60,215,1994
International Agency for Research on Cancer (IARC)Cancer Review:Animal Sufficient EvidenceIMEMDT 71,1015,1999
International Agency for Research on Cancer (IARC)Cancer Review:Human Inadequate EvidenceIMEMDT 60,215,1994
International Agency for Research on Cancer (IARC)Cancer Review:Human No Adequate DataIMEMDT 71,1015,1999
International Agency for Research on Cancer (IARC)Cancer Review:Group 2BIMEMDT 71,1015,1999
TOXICOLOGY REVIEWCBINA8 135-136,27,2001
TOXICOLOGY REVIEWCBINA8 135-136,65,2001
TOXICOLOGY REVIEWMUREAV 543,201,2003
TOXICOLOGY REVIEWMUREAV 584,1,2005
TOXICOLOGY REVIEWMUREAV 751,49,2012
TOXICOLOGY REVIEWREPTED 33,269,2012
TOXICOLOGY REVIEWFCTOD7 49,1877,2011
TOXICOLOGY REVIEWFCTOD7 49,2921,2011
TOXICOLOGY REVIEWMUREAV 802,1,2016
TOXICOLOGY REVIEWFCTOD7 94,93,2016

Standards and Regulations

OrganizationStandardReference
Occupational Exposure Limit-GERMANYMAK 3 ppm (8.5 mg/m3), 2011
Occupational Exposure Limit-JAPAN2B carc, MAY2012
Occupational Exposure Limit-POLANDMAC(time-weighted average) 100 mg/m3, MAC(short term exposure limit) 300 mg/m3, JAN1999
Occupational Exposure Limit-RUSSIAshort term exposure limit 40 mg/m3, JUN2003
Occupational Exposure Limit-SWITZERLANDMAK-week 3 ppm (8.5 mg/m3), KZG-week 24 ppm (68 mg/m3), JAN2011

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Occupational Exposure Survey 1983Hazard Code 40940; Number of Industries 6; Total Number of Facilities 123; Number of Occupations 15; Total Number of Employees Exposed 3703; Total Number of Female Employees Exposed 578
National Occupational Hazard Survey 1974Hazard Code 40940; Number of Industries 36; Total Number of Facilities 2278; Number of Occupations 43; Total Number of Employees Exposed 58102

Status in Federal Agencies

OrganizationReference
EPA TSCA Section 8(b) CHEMICAL INVENTORY
EPA TSCA Section 8(e) Risk Notification, 8EHQ-0293-8707
EPA TSCA TEST SUBMISSION (TSCATS) DATA BASE, JANUARY 2001
NCI Carcinogenesis Studies (inhal);clear evidence:rat
NTP 11th Report on Carcinogens,2004:Reasonably anticipated to be a human carcinogen
NTP Toxicity studies, RPT# TOX-31, October 2000
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