Classification of residual solvents by risk assessment

Class 1 solvents, solvents to be avoided, known as human carcinogens or strongly suspected carcinogens and environmental hazards. 

Class 2 solvents, solvents to be limited. Nongenotoxic animal carcinogens or possible causative agents of other irreversible toxicities such as neurotoxicity or teratogenicity. Solvents suspected of other significant but reversible toxicities. 

Class 3 solvents. Solvents with low toxic potential to man no health-based exposure limit is needed. Class 3 solvents have permitted daily exposures (PDE) of 50 mg or more per day. 

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