National Institute for Occupational Safety and Health

“ Sample stability was studied using solutions of 2,4- and 2,6-toluenediamine in sampling medium at levels corresponding to 0.89 and 0.74 μg per sample, respectively. The recoveries, ranging from 97% to 106%, suggested the samples were stable under the conditions of storage—1, 7, and 14 days at room temperature in the dark. The potential for interference from isocyanates was investigated by drawing air containing 7.3 μg each of 2,4- and 2,6-toluene diisocyanate through samples of 0.9 μg each of 2,4- and 2,6-toluenediamine in 15 mL of sampling medium. ”

“ Take adequate precautions while handling pentane. SAMPLING: 1.
Calibrate each personal sampling pump with a representative sampler in line. 2.
Transfer 15.0 mL sampling medium to an impinger. 3.
Connect the assembled impinger to a sampling pump. 4.
Sample 30 to 500 L of air at an accurately measured sampling rate of 1 L/min. When it is necessary to add solvent for proper impinger operation during sampling, add only toluene. NOTE:
The reagent in the sampling medium reacts with isocyanates present to form ureas, thus preventing reaction of the isocyanate with the toluenediamines. ”

“ D.V. Sweet, Ed., U. S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Standards Development and Technology Transfer. ”