2H-Azepin-2-one, hexahydro-

RTECS #
CM3675000
CAS #
105-60-2
See: NMAM or OSHA Methods
Updated
December 2018
Molecular Weight
113.18
Molecular Formula
C6H11NO
Synonyms
1,6-Hexolactam
1-Aza-2-cycloheptanone
2-Azacycloheptanone
2H-Azepin-7-one, hexahydro-
2-Ketohexamethyleneimine
2-Ketohexamethylenimine
2-Oxohexamethyleneimine
2-Oxohexamethylenimine
2-Perhydroazepinone
6-Aminocaproic acid lactam
6-Aminohexanoic acid cyclic lactam
6-Caprolactam
6-Hexanelactam
A1030
Aminocaproic lactam
Caprolactam
Caprolactam monomer
Caprolactam, fume
Caprolattame (French)
Capron PK4
Cyclohexanone iso-oxime
e-Kaprolaktam (Czech)
epsilon-Caprolactam
epsilon-Caprolactam (ACGIH)
Epsylon kaprolaktam (Polish)
Extrom 6N
Hexahydro-2-azepinone
Hexahydro-2H-azepin-2-one (9CI)
Hexamethylenimine, 2-oxo-
Hexanoic acid, 6-amino-, cyclic lactam
Hexanoic acid, 6-amino-, lactam
Hexanolactam
Hexanone isoxime
Hexanonisoxim (German)
Kapromine
NCI-C50646
omega-Caprolactam
Stilon

Skin and Eye Irritation and References

Route/OrganismDoseEffectReference
eye /rabbit 20 mg/24H moderate85JCAE -,883,1986
skin /rabbit 500 mg/24H mild85JCAE -,883,1986

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
body fluid assayovary/rat76 mg/kgMUREAV 143,263,1985
Cytogenetic Analysislymphocyte/human270 mg/LPMRSDJ 5,457,1985
Cytogenetic Analysislung/hamster8 gm/LPMRSDJ 5,427,1985
DNA Damageintraperitoneal/rat580 mg/kgMUREAV 224,379,1989
DNA Damageintraperitoneal/mouse580 mg/kgMUREAV 224,379,1989
DNA inhibitionfibroblast/human1 mmol/LNEOLA4 33,699,1986
gene conversion and mitotic recombination/Saccharomyes cerevisiae400 mg/LPMRSDJ 5,271,1985
micronucleus testmultiple/non-mammalian species100 ppmMUTAEX 4,17,1989
morphological transformembryo/hamster100 mg/LTIVIEQ 2,103,1988
morphological transformembryo/mouse2500 mg/LPMRSDJ 5,639,1985
mutation in microorganisms/Saccharomyes cerevisiae100 mg/L (+/-enzymatic activation step)PMRSDJ 5,271,1985
phage inhibition capacity/Escherichia coli1950 µg/wellMUREAV 260,349,1991
sex chromosome loss and nondisjunctionoral/Drosophila melanogaster5 mmol/LMUREAV 224,339,1989
sex chromosome loss and nondisjunctionlymphocyte/human25 mmol/LMUREAV 224,333,1989
sister chromatid exchangeovary/hamster125 mmol/LMUREAV 224,333,1989
specific locus testoral/Drosophila melanogaster5 mmol/LPMRSDJ 5,313,1985
specific locus testintraperitoneal/mouse500 mg/kgMUREAV 224,369,1989
sperm morphologyinhalation/rat125 mg/m3/10WGTPZAB 19(10),40,1975

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
inhalation/rat 125 mg/m3/24H (76D male)Reproductive: Paternal effects: Spermatogenesis (including genetic material, sperm morphology, motility, and count)GTPZAB 19(10),40,1975
inhalation/rat 473 mg/m3/4H (1-5D pregnant)Reproductive: Effects on fertility: Pre- implantation mortality (e.g., reduction in number of implants per female; total number of implants per corpora lutea)

Reproductive: Effects on embryo or fetus: Fetal death
GISAAA 34(7),25,1969
inhalation/rat 139 mg/m3/4H (6-12D pregnant)Reproductive: Effects on fertility: Pre- implantation mortality (e.g., reduction in number of implants per female; total number of implants per corpora lutea)GISAAA 34(7),25,1969
inhalation/rat 473 mg/m3/4H (60D prior to copulation)Reproductive: Maternal effects: Menstrual cycle changes or disordersGTPZAB 13(10),22,1969
oral/rabbit 3450 mg/kg (6-28D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)JJATDK 7,317,1987
oral/rabbit 2500 mg/kg (6-15D pregnant)Reproductive: Effects on newborn: Growth statistics (e.g., reduced weight gain)NTIS** OTS0537802
oral/rat 10 gm/kg (6-15D pregnant)Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)JJATDK 7,317,1987
oral/rat 10 gm/kg (6-15D pregnant)Reproductive: Effects on newborn: Growth statistics (e.g., reduced weight gain)NTIS** OTS0537802
oral/rat 10 gm/kg (6-15D pregnant)Reproductive: Other effects on female

Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)
NTIS** OTS0557708

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/human lowest published toxic concentration: 100 ppmLung, Thorax, or Respiration: CoughAIHAAP 34,384,1973
inhalation/mouse lethal concentration (50 percent kill): 450 mg/m3Behavioral: Muscle contraction or spasticityGTPZAB 10(10),54,1966
inhalation/mouse lethal concentration (50 percent kill): 450 mg/m3TOVEFN (1),20,2001
inhalation/rat lethal concentration (50 percent kill): 300 mg/m3TOVEFN (1),20,2001
inhalation/rat lethal concentration (50 percent kill): 300 mg/m3/2H85GMAT -,32,1982
intraperitoneal/mouse lethal dose (50 percent kill): 650 mg/kgBehavioral: Convulsions or effect on seizure threshold

Behavioral: Antipsychotic

Behavioral: Analgesia
JPMSAE 60,1058,1971
intraperitoneal/rat lowest published lethal dose: 800 mg/kgBehavioral: Convulsions or effect on seizure threshold

Gastrointestinal: Changes in structure or function of salivary glands

Nutritional and Gross Metabolic: Body temperature decrease
BJIMAG 11,1,1954
intravenous/mouse lethal dose (50 percent kill): 480 mg/kgIMEMDT 39,247,1986
intravenous/rabbit Lethal dose: >300 mg/kgBehavioral: Convulsions or effect on seizure threshold

Gastrointestinal: Changes in structure or function of salivary glands

Nutritional and Gross Metabolic: Body temperature decrease
BJIMAG 11,1,1954
oral/mouse lethal dose (50 percent kill): 930 mg/kgBehavioral: Muscle contraction or spasticity

Lung, Thorax, or Respiration: Dyspnea
GTPZAB 10(10),54,1966
oral/rat lethal dose (50 percent kill): 1210 mg/kgEye: Chromodacryorrhea

Behavioral: Convulsions or effect on seizure threshold

Nutritional and Gross Metabolic: Body temperature decrease
NTPTR* NTP-TR-214,1982
skin/rabbit lethal dose (50 percent kill): 1410 µL/kgAIHAAP 30,470,1969
skin/rat lethal dose (50 percent kill): >2 gm/kgNTIS** OTS0557720
subcutaneous/frog lowest published lethal dose: 2800 mg/kgAutonomic Nervous System: Other (direct) parasympathomimetic

Behavioral: Somnolence (general depressed activity)

Behavioral: Convulsions or effect on seizure threshold
AEXPBL 50,199,1903
subcutaneous/guinea pig lowest published lethal dose: 950 mg/kgMELAAD 43,124,1952
subcutaneous/mouse lethal dose (50 percent kill): 750 mg/kgIMEMDT 39,247,1986
unreported route/mouse lethal dose (50 percent kill): 930 mg/kgBehavioral: Convulsions or effect on seizure threshold

Kidney, Ureter, and Bladder: Urine volume increased
GISAAA 55(10),33,1990
unreported route/rabbit lethal dose (50 percent kill): 1 gm/kgBehavioral: Convulsions or effect on seizure threshold

Kidney, Ureter, and Bladder: Urine volume increased
GISAAA 55(10),33,1990
unreported route/rat lethal dose (50 percent kill): 580 mg/kgBehavioral: Convulsions or effect on seizure threshold

Kidney, Ureter, and Bladder: Urine volume increased
GISAAA 55(10),33,1990

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
inhalation/rat lowest published toxic concentration: 243 mg/m3/6H/13W- intermittentOlfaction: Other olfaction effects

Lung, Thorax, or Respiration: Dyspnea

Lung, Thorax, or Respiration: Other changes
TOSCF2 44,197,1998
inhalation/rat lowest published toxic concentration: 5960 mg/kg/82D- continuousKidney, Ureter, and Bladder: Other changes in urine composition

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
GISAAA 33(1),22,1968
intraperitoneal/rat lowest published toxic dose: 9100 mg/kg/26W- intermittentBlood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Blood: Changes in other cell count (unspecified)

Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field
MEPAAX 18,357,1967
oral/rat lowest published toxic dose: 42 gm/kg/8W- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gainARZNAD 9,9,1959
oral/rat lowest published toxic dose: 6750 mg/kg/2W- intermittentNutritional and Gross Metabolic: Weight loss or decreased weight gainNTIS** OTS0555505

Reviews

OrganizationStandardReference
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-time-weighted average 5 mg/m3 (inhal, vapor)DTLVS* TLV/BEI,2013
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-Not suspected as a human carcinogenDTLVS* TLV/BEI,2013
International Agency for Research on Cancer (IARC)Cancer Review:Animal NO EVIDENCEIMEMDT 39,247,1986
International Agency for Research on Cancer (IARC)Cancer Review:Animal No EvidenceIMEMDT 71,383,1999
International Agency for Research on Cancer (IARC)Cancer Review:Human No Adequate DataIMEMDT 39,247,1986
International Agency for Research on Cancer (IARC)Cancer Review:Human No Adequate DataIMEMDT 71,383,1999
International Agency for Research on Cancer (IARC)Cancer Review:Group 4IMEMDT 71,383,1999
TOXICOLOGY REVIEWFCTOD7 47,1287,2009
TOXICOLOGY REVIEWTOLED5 199,203,2010
TOXICOLOGY REVIEWFCTOD7 55,596,2013
TOXICOLOGY REVIEWFCTOD7 109,1,2017
TOXICOLOGY REVIEWRTOPDW 55,43,2009

Standards and Regulations

OrganizationStandardReference
Occupational Exposure Limit IN ARGENTINA, BULGARIA, COLOMBIA, JORDAN check ACGIH TLV;
Occupational Exposure Limit IN SINGAPORE, VIETNAM check ACGIH TLV
Occupational Exposure Limit-AUSTRALIAtime-weighted average 1 mg/m3, short term exposure limit 3 mg/m3 (dust and vapor), JUL2008
Occupational Exposure Limit-AUSTRALIAtime-weighted average 1 mg/m3, short term exposure limit 3 mg/m3 (dust), JUL2008
Occupational Exposure Limit-AUSTRIAMAK-TMW 5 mg/m3;KZW 40 mg/m3, inhal, 2007
Occupational Exposure Limit-BELGIUMtime-weighted average 1 mg/m3, short term exposure limit 3 mg/m3 (dust), MAR2002
Occupational Exposure Limit-BELGIUMtime-weighted average 2.2 ppm (10 mg/m3), (vapor), MAR2002
Occupational Exposure Limit-BELGIUMshort term exposure limit 8.7 ppm (40 mg/m3) (vapor), MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 1 mg/m3 (dust), MAY2011
Occupational Exposure Limit-DENMARKtime-weighted average 2 ppm (10 mg/m3) (vapor), MAY2011
Occupational Exposure Limit-ECtime-weighted average 10 mg/m3;short term exposure limit 40 mg/m3 (dust, vapor), JUN2000
Occupational Exposure Limit-FINLANDtime-weighted average 10 mg/m3, short term exposure limit 40 mg/m3, NOV2011
Occupational Exposure Limit-FRANCEVME 10 mg/m3 (dust, vapor), VLE 40 mg/m3 (dust, vapor), FEB2006
Occupational Exposure Limit-GERMANYMAK 5 mg/m3 (dust, vapor, inhal.), 2011
Occupational Exposure Limit-HUNGARYtime-weighted average 10 mg/m3, short term exposure limit 40 mg/m3, SEP2000
Occupational Exposure Limit-ICELANDtime-weighted average 1 mg/m3, dust, NOV2011
Occupational Exposure Limit-KOREAtime-weighted average 1 mg/m3, short term exposure limit 3 mg/m3, 2006
Occupational Exposure Limit-KOREAtime-weighted average 5 ppm (20 mg/m3), short term exposure limit 10 ppm (40 mg/m3), 2006
Occupational Exposure Limit-MEXICOtime-weighted average 1 mg/m3 (dust), 2004
Occupational Exposure Limit-MEXICOtime-weighted average 5 ppm (20 mg/m3);short term exposure limit 3 mg/m3 (vapor), 2004
Occupational Exposure Limit-MEXICOshort term exposure limit 10 ppm (40 mg/m3) (vapor), 2004
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 5 ppm (23 mg/m3); short term exposure limit 10 ppm (46 mg/m3) (vapor), JAN2002
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 1 mg/m3; short term exposure limit 3 mg/m3 (dust), JAN2002
Occupational Exposure Limit-NORWAYtime-weighted average 5 ppm (25 mg/m3), moist, JAN1999
Occupational Exposure Limit-PERUtime-weighted average 5 mg/m3, JUL2005
Occupational Exposure Limit-POLANDMAC(time-weighted average) 10 mg/m3 (dust), JAN1999
Occupational Exposure Limit-RUSSIAshort term exposure limit 10 mg/m3, JUN2003
Occupational Exposure Limit-SWEDENtime-weighted average 5 mg/m3;short term exposure limit 10 mg/m3, (dust, vapour), JUN2005
Occupational Exposure Limit-SWITZERLANDMAK-week 5 mg/m3, inhal, JAN2011
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 1 mg/m3 (dust), 2003
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 20 mg/m3 (fume), 2003
Occupational Exposure Limit-UNITED KINGDOMtime-weighted average 1 mg/m3; short term exposure limit 3 mg/m3 (dust), OCT2007
Occupational Exposure Limit-UNITED KINGDOMtime-weighted average 10 mg/m3; short term exposure limit 20 mg/m3 (dust, vapor), OCT2007

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO CAPROLACTAM, dust-air10H time-weighted average 1 mg/m3;short term exposure limit 3 mg/m3NIOSH* DHHS #95-121,1995
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO CAPROLACTAM, vapor-air10H time-weighted average 0.22 ppm;short term exposure limit 0.66 ppmNIOSH* DHHS #95-121,1995
National Occupational Exposure Survey 1983Hazard Code 83732; Number of Industries 12; Total Number of Facilities 812; Number of Occupations 19; Total Number of Employees Exposed 25091; Total Number of Female Employees Exposed 8291
National Occupational Hazard Survey 1974Hazard Code 83732; Number of Industries 14; Total Number of Facilities 955; Number of Occupations 14; Total Number of Employees Exposed 6208

Status in Federal Agencies

OrganizationReference
EPA GENETOX PROGRAM 1988, Negative: Carcinogenicity-mouse/rat
EPA GENETOX PROGRAM 1988, Negative: CHO gene mutation
EPA TSCA Section 8(b) CHEMICAL INVENTORY
EPA TSCA Section 8(d) unpublished health/safety studies
EPA TSCA TEST SUBMISSION (TSCATS) DATA BASE, JANUARY 2001
NCI Carcinogenesis Studies (feed);no evidence:mouse,rat
On EPA IRIS database
Page last reviewed: November 16, 2018