Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 202-429-0 | CAS number: 95-53-4
Endpoint summary
Administrative data
Link to relevant study record(s)
Description of key information
o-Toluidine is rapidly absorbed via gastrointestinal tract and is rapidly distributed, metabolized and excreted mainly via urine. although there are no special toxicokinetik data on absorption via skin and respiratary tract , absorptions via this administration routes is shown by data from acute toxicity.
Key value for chemical safety assessment
Additional information
OECD/SIDS of o-toluidine published by UNEP in 2006 summarizes:
Studies in Animals:
There are no special toxicokinetic data on absorption via skin and respiratory tract but respective acute toxicity studies indicate absorption via these administration routes.
Following oral application of 500 mg toluidine/kg bw to rats a half-life time of plasma elimination of 12 to 15 hours was derived (Brock, Hundley and Lieder, 1990); i.v. application of app. 111 mg/kg bw to dogs yielded a half-life time of plasma elimination of half an hour (Kiese, 1963). 48 hours following subcutaneous injection of labelled o-toluidine hydrochloride into rats, Son, Everett and Fiala (1980) detected radioactivity in decreasing range: liver > kidney > spleen, colon > lung and bladder. In another study 72 hours following oral application to rats, radioactivity was detected in decreasing range: whole blood > spleen > kidney > liver > subcutaneous abdominal fat > lung > heart > abdominal skin> bladder >gastrointestinal tract > bone marrow > brain > muscle > testes (Brock, Hundley and Lieder, 1990). The results from metabolism study in rats show that N-acetylation and hydroxylation at the position 4 of the aromatic ring of o-toluidine are the major metabolic pathways in rats. Minor pathways include hydroxylation at position 6, oxidation of the methyl-group and oxidation of the amino-group. Sulphate conjugates predominate over glucuronides by a ratio of 6:1. The metabolites which were found included azoxytoluene, onitrosotoluene, N-acetyl-o-toluidine, N-acetyl-o-aminobenzyl alcohol, 4-amino-m-cresol, N-acetyl- 4-amino-m-cresol, anthranilic acid, N-acetyl-anthranilic acid, 2-amino-m-cresol, other unidentified substances and unchanged o-toluidine (Son, Everett and Fiala, 1980).
In rats, unchanged o-toluidine and the metabolites are largely excreted in the urine: 48 hours after s.c. injection up to 83 % of the dose (Son, Everett and Fiala, 1980) and 72 hours after oral application up to 94.7 % of the dose (Cheever, Richards and Plotnick, 1980). Faecal excretion and exhalation of the substance is minimal with up to 3.5 % and 1.46 % of the dose (Son, Everett and Fiala, 1980).
Studies in humans
Biological Monitoring to assess human exposure to o-oluidine indicates that absorption may occur though inhalation and dermal contact; however, quantitative information was not identified. o-toluidine binds to hemoglobin. N-acetylated metabolites of o-toluidine are eliminated in the urine (CICAD 1988)
Overall conclusion
o-Toluidine is rapidly absorbed via gastrointestinal tract and is rapidly distributed, metabolized and excreted mainly via urine. Although there are no special toxicokinetic data on absorption via skin and respiratory tract, absorption via these administration routes is shown by data from acute toxicity studies
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
