A Sampling and Analytical Method for Monitoring Low Ppm Air Concentrations of 1,3-Butadiene

Abstract

Evidence of the carcinogenic effects of 1,3-butadiene has caused OSHA to review the current standard which is 1000 ppm. Since this standard could be lowered significantly it was necessary to determine if low ppm levels of 1,3-butadiene could be monitored reliably. An evaluation of NIOSH method S91 at low ppm levels showed it would be inadequate because of sample instability. Therefore, a new procedure was developed which provides the desired sample stability. The new procedure was evaluated using established OSHA guidelines, which required the collection of samples from controlled test atmospheres for determination of sampler capacity and sample stability. Samples were collected with a coconut-shell charcoal which had been washed with phosphoric acid and coated with 10% by weight 4-tert-butylcatechol. The sampling tube contained a 100-mg section followed by a 50-mg section of adsorbent. After samples were desorbed with carbon disulfide, analyses were performed with a gas Chromatograph equipped with a flame ionization detector. Samples collected from a 1-ppm 1,3-butadiene test atmosphere and stored for 18 days under refrigeration gave an average recovery of 92% when analyzed. Similar samples which were collected with commercially available coconut-shell charcoal tubes gave an average recovery of only 34% when analyzed immediately after collection. Hendricks, W.D.; Schultz, G.R.: A sampling and analytical method for monitoring low ppm air concentrations of 1,3-butadiene.