NIOSH (1987) states: " Epidemiologic studies of various groups of solvent-exposed workers have demonstrated statistically significant chronic changes in peripheral nerve function (sensory and motor nerve conduction velocities and electromyographicabnormalities) that persisted for months to years following cessation of exposure. Epidemiologic studies have also shown statistically significant increases in neurobehavioural effects in workers chronically exposed to organic solvents. These effects include disorders characterised by reversible subjective symptoms (fatigability, irritability, and memory impairment), sustained changes in personality or mind (emotional instability and diminished impulse control and motivation), and impaired intellectual function (decreased concentration ability, memory, and learning ability). Among organic solvent abusers, the most severe disorders reported are characterised by irreversible deterioration in intellect and memory... accompanied by structural CNS damage."