Trimethylsilanol was studied for oral toxicity in rats in a 28-day repeat dose toxicity test at doses of 0, 10, 40, 160 and 640 mg/kg. Decreased spontaneous motor activity and staggering gait were observed in both sexes given 640 mg/kg. Moreover, gait difficulty was observed in males given 640 mg/kg. Body weight gain tended to be suppressed and fibrinogen increased in both sexes given 640 mg/kg, along with absolute thymus decrease and relative liver weight increase in females. The changes in body weights in males and in relative liver weights in females were still found at the end of a 14-day recovery period . The NOEL for repeat dose toxicity is considered to be 160 mg/kg/day for both sexes.
Trimethylsilanol was not mutagenic in Salmonella typhimurium TA100, TA1535, TA98 and TA1537 or Escherichia coli WP2 uvrA.
Trimethylsilanol did not induce structural chromosomal aberrations or polyploidy in CHL/IU cells with or without an exogenous metabolic activation system.