Accelerators and stabilizers used in natural rubber and many types of synthetic rubber are often derived from dialkylamines. It has been found that raw polymers, compounded uncured elastomers, and cured rubber parts containing these dialkylamino compounds emit low concentrations of the corresponding dialkylnitrosamine (R₂N-N=O) when they are heated. Exposure of operators working with these materials can be reduced below a level of 50 parts per trillion by volume in air by use of ventilation velocities of about 50 ft/min. around the operation. The analytical method is described.