Lack of DNA-strand breaks in rat testicular cells after in vivo treatment with sodium fluoride.

Oral administration of up to 84 mg/kg of NaF to adult male rats did not induce DNA-strand breaks in testicular cells when measured by alkaline elution. Although plasma fluoride levels were as high as 12 ppm is rats given 84 mg/kg of NaF, testicular fluoride levels in most cases were only 10-20% of plasma levels. Fluoride did not accumulate in the testes after 5 daily treatments. Therefore, it is unlikely that NaF, even at high doses, poses a hazard with respect to heritable genetic effects.