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Registry of Toxic Effects of Chemical Substances (RTECS)

Isoprene

RTECS #

NT4037000

CAS #

78-79-5; 78006-92-5

Updated

July 2013

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

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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