Registration Dossier

Toxicological information

Basic toxicokinetics

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Administrative data

Endpoint:
basic toxicokinetics
Type of information:
other: Information on major hydrolysis product of the registered substance (released rapidly on contact with water/moisture).
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Authoritative review of fluoride exposure, toxicokinetics and toxicity by an expert committee.

Data source

Reference
Reference Type:
review article or handbook
Title:
Fluoride in Drinking Water: A Scientific Review of EPA's Standards
Author:
Committee on Fluoride in Drinking Water, NRC
Year:
2006
Bibliographic source:
US National Academy of Sciences

Materials and methods

Principles of method if other than guideline:
Detailed expert review of fluoride, addressing all aspects related to possible adverse effects of its presence in drinking water.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Fluoride is a major hydrolysis product of the rapid reaction of LiPF6 with water.

Test animals

Species:
other: Data obtained from both animals and man reviewed

Results and discussion

Any other information on results incl. tables

Hydrogen fluoride is formed from ingested fluoride in the stomach, and is the principal form in which fluoride is absorbed here; it passes easily through the gastric epithelium. Dissociation to free fluoride (F-) follows. Fluoride half-life in the GI tract is about 30 minutes, with high absorption efficiency (typically 70 – 90%: nearly 100% for soluble inorganic fluorides). It becomes incorporated in skeletal bone and in teeth (some 99% of the total body fluoride being within bone). The general pattern of absorption and distribution appears generally similar in animals and man, but it has been observed that rats may require higher chronic exposure to fluoride to achieve comparable plasma and bone concentrations: about 5 times higher concentration in water to establish similar plasma concentrations; incorporation into bone about 18 times more in man than in rats under normal dietary conditions.

Applicant's summary and conclusion

Conclusions:
Excessive intake of fluoride can lead to fluorosis of the dental enamel or skeletal bone due to retention and accumulation in these body parts.