Reagent Xylene Methyl tertiary-butyl ether Hazardous substance symbol harmful (Xn) irritant (Xi) Maximum permissible concentration 100 mg/m3 300 mg/m3 Maximum permissible momentary concentration 350 mg/m3 not established Topical exposure in rabbits intense irritation both eyes and skin slight irritation of the eyes and no irritation of the skin Inhalatory systemic exposure in rats (lethal concentration,50%) 5 g/m3 23.57 g/m3

Table 1: Safety characteristics of the used paraffin solvents: xylene and methyl tertiary-butyl ether.