National Toxicology Program

CASRN: 103-90-2

Formula: C8-H9-N-O2

Synonyms/Common Names:

• APAP
• 4-HYDROXYACETANILIDE
• N(4-HYDROXYPHENYL)-ACETAMIDE (9CI)

Known Uses:

MANUFACTURE OF AZO DYES, ANALGESIC, INTERMEDIATE FOR PHARMACEUTICALS (HSDB 1990); DERIVATIVE OF P-AMINOPHENOL

Short-Term Toxicity

• 2-DAY (Gavage)  (C55801E) Subchronic Toxicology Review 
  • Rats: F344/N; Rats: F344/N
  • Dose: RATS ONLY: 0, 50, 150, 1000, OR 2000 MG/KG; 6/GROUP
• 14-Day (Dosed-Feed)  (C55801) Completed 
  • NTIS No. PB93-227478  (Peer Review 11/19/1990)
    Citation: Toxicology and Carcinogenesis Studies of Acetaminophen (CAS No. 103-90-2) in F344 Rats and B6C3F1 Mice (Feed Studies)
  • Rats: F344/N; Mice: B6C3F1
• 13-Week (Dosed-Feed)  (C55801) Completed 
  • NTIS No. PB93-227478  (Peer Review 11/19/1990)
    Citation: Toxicology and Carcinogenesis Studies of Acetaminophen (CAS No. 103-90-2) in F344 Rats and B6C3F1 Mice (Feed Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Dose: R&M:0,0.08,2.50%/10 PER GROUP

Long-Term Carcinogenicity

• 2-YEAR (Dosed-Feed)  (C55801) Report Complete 
  • TR-394 (NTIS No. PB93-227478)  (Peer Review 11/19/1990)
    Toxicology and Carcinogenesis Studies of Acetaminophen (CAS No. 103-90-2) in F344 Rats and B6C3F1 Mice (Feed Studies)
  • Rats: F344/N; Mice: B6C3F1
  • Carcinogenesis Results
  • Male Rats No Evidence 
  • Female Rats Equivocal Evidence 
  • Male Mice No Evidence 
  • Female Mice No Evidence 
  • Dose: R&M:0,.06,.3,.6%/60 PER GROUP

Special Studies

• C. elegans  (S0943) Completed 
  • Nematode: C. elegans

Genetic Toxicology

• In Vitro Cytogenetics (CA/SCE)  (034886) Completed 
  • Chromosome Aberation Positive 
  • Sister Chromatid Exchange Positive 
• Salmonella  (413793) Completed 
  • Citation: Haworth, S., Lawlor, T., Mortelmans, K., Speck, W., and Zeiger, E. Salmonella mutagenicity test results for 250 chemicals Environ. Mutagen. Vol. 5 (Suppl 1) (1983) 3-142
  •  Negative 

Organ Systems Toxicity

• 120 D MINIMUM Continuous Breeding (Dosed-Feed)  (RACB83079) Completed 
  • NTIS No. PB85-204667
    Citation: Final Report - Acetaminophen: Reproduction and Fertility Assessment In CD-1 Mice When Administered in the Feed
  • M/F Mice: Swiss
  • Dose: 0,.31,.62,1.25,2.5,5.0%; 0,.25,.5,1%; N/A; 0,1%