Industry-wide studies report of an in-depth survey at Dow Chemical U. S. A. , Texas Division, Freeport, Texas

Environmental and breathing-zone samples were analyzed for 1,3-butadiene at Dow Chemical USA, Freeport, Texas in May, 1985. Company monitoring data was reviewed. Engineering controls were evaluated. The time-weighted average 1,3-butadiene exposure across all job categories was less than 1.2 parts per million (ppm). The OSHA standard for 1,3-butadiene is 1,000ppm. Process technicians had the highest average exposure, 1,16ppm. A process technician performing bomb sampling in the process area had the highest short-term (20 minute) exposure, 10.44ppm. The analytical data generally agreed with company monitoring data. Engineering controls consisted of fitting all pumps in the storage and recovery areas with dual mechanical seals, using on/line gas chromatographic or closed-loop manual-sampling systems for obtaining quality-control samples, using local exhaust ventilation in the laboratories, and monitoring loading of 1,3-butadiene into rail tank cars with magnetic and slip-tube gauges. The company required all employees to wear appropriate personal-protective equipment. The authors conclude that 1,3-butadiene exposures at the facility are maintained below 2ppm. The NIOSH data agrees with company historical exposure data. They recommend modifying process values on the pumps and equipping all rail tank cars with magnetic gauges for monitoring filling operations.