Organic solvent exposure is known to give rise to a variety of manifestations in the nervous system both in man and in animals. Cardiac and skeletal muscle can also be affected, and strange collagen-like diseases, arthritis and arthralgia have been reported. In this work PVG rats were exposed to inhalation of toluene, commercial hexane, an industrial steel primer, and a cold vulcanizer for 4 months. No signs of synovitis appeared, either macroscopically or histologically, and there were no systemic signs of inflammation as detected by increased acute phase reactants.