A comparative study of the effects of carbon monoxide and methylene chloride on human performance.

The purpose of this investigation was to determine whether similar carboxyhemoglobin (COHb) values obtained from inhaling carbon monoxide or methylene chloride have the same behavioral effects. The effects were assessed by the performance of 12 humans on a visual-manual, dual-task, and an auditory vigilance task. The results indicated that both substances in concentrations sufficient to produce 5-percent COHb significantly impaired human performance under difficult or demanding task conditions. The conclusion was that carbon monoxide, the main metabolite of methylene chloride, was responsible for the observed performance decrements.