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: 232-235-1
CAS number: 7790-98-9
Perchlorate has been shown to induce benign thyroid tumours (thyroid follicle epithelial cell adenomas) in rodents in three studies:- in a Klimisch 4, non-GLP, non-guideline subchronic study in mouse, at the only tested dose of ~1200 mg/kg/day* (Gauss 1972 under 751)- in a Klimisch 4, non-GLP, non-guideline carcinogenicity study in rat, at the only tested dose of ~630 mg/kg/day* (Kessler 1966 under 77)- in a Klimisch 2, adequately GLP/guideline-compliant 2-generation study in rat, in 2/30 F1 male pups exposed for 125-142 or up to** 167-184 days at 30 mg/kg/day (York 1999 under 781). This is the most reliable and sensitive value, retained as a basis for a carcinogenicity LOAEL. The NOAEL (3 mg/kg/day) is not retained because of the high dose spacing.*: indicative dose-level estimated as ammonium perchlorate equivalent by RSS/CSR author, see details in each RSS**: including or excluding the gestational and lactational periods (in which transplacental and milk transfer to F1 individuals is known, but not quantified)
Potassium perchlorate was provided at 1% in drinking
water to young male Wistar rats (mean: 169 g at initiation). The effects
CSR/RSS author estimated as follows the equivalent
ammonium perchlorate dose-level:
- considering MWs of 138.5 and 117.5 g/mol for KClO4 and
NH4ClO4 respectively, 1% KClO4 is equivalent to 8.5 mg/mL of NH4ClO4
- a mean daily water consumption of only 25 mL is
hypothesized (in absence of data) based on the low weight of the rats
- the mean body weight was 169 g (beginning of study) and
383 g (end of study)
- therefore, the estimated dose-level ranges 550 (end of
study) to 1260 (beginning of study) mg/kg/day, with a time-weighed
average around 630 mg/kg/day.
Perchlorate is a goitrogen; goitrogens are known to
induce thyroid stimulation, possible benign tumours at extreme exposure
levels/durations, but a causal relationship with malignant thyroid
tumours is not established and seems unlikely from the expert positions
The National Academy of Sciences panel on perchlorate
concluded that perchlorate is unlikely to cause cancer (National Academy
of Sciences report, "Health Implications of Perchlorate Ingestion,"
This is consistent with the view of US FDA (Poirer et
al., "An FDA Review of Sulfamethazine toxicity", December 1999):
This is further consistent with the previous US FDA
expert paper "Assessment of thyroid follicular cell tumours", ref.
EPA/630/R-97/002, March 1998:
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.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again