Is it safe to apply the additivity rule to evaluating health effects of exposure to Farbasol?

Int J Occup Med Environ Health. 1999;12(1):85-92.

Abstract

Neurotoxic and sensory respiratory irritation effects of Farbasol in male rats and male Balb/C mice were investigated in condition of acute inhalation exposure. Rotarod performance and pain sensitivity behaviour were tested in rats exposed to Farbasol at concentrations of 4665-9622 mg/m3 immediately after termination of a four-hour exposure. The respiratory rate was measured in mice by the whole body plethysmographic method in 6 min duration exposure to various concentrations of Farbasol. Exposure to Farbasol resulted in concentration-dependent disturbances in rotarod performance and decrease in pain sensitivity in rats, and depression of respiratory rate in mice. The EC50 value for rotarod performance behaviour disturbances was 5497 mg/m3 and for pain sensitivity EC50 was 6589 mg/m3. The concentration depressing the respiratory rate to 50% (RD50) was 3139 mg/m3. The comparison of Farbasol EC50 and RD50 values and its individual constituents such as trimethylbenzene isomers and 4-ethyl toluene established in similar experimental conditions indicate their similar toxic effects potency. Application of additivity rule for establishing the MAC value for Farbasol seems to be safe.

MeSH terms

  • Animals
  • Benzene Derivatives / pharmacology*
  • Central Nervous System / drug effects
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Motor Activity / drug effects
  • Occupational Exposure*
  • Rats
  • Rats, Wistar
  • Regression Analysis
  • Respiration / drug effects
  • Solvents / pharmacology*

Substances

  • Benzene Derivatives
  • Solvents
  • farbasol