Document 2jE9y5nB43RDKJXm6pw67kJ4r

M onsanto *h C " LOC `1 'ON Dept, of Medicine & Environm ental Health i o p ifC* 1/21/85 Tetrethal Monitoring Results _T TI Uni fchprgp r _s-- fl?WR -- J. L A. W T O : R. Nair G. Levinskas W. B. Papageorge F. E. Kearney Monitoring results for tetrathal are available since 1976. The method employed, however, measured total dust and assumed that everything collected was tetrachlorophthalic anhydride. This technique tends to over estimate the actual exposure and thus the results reported may be slightly higher than actual tetrathal concentrations. Most of the samples were taken during the two high exposure jobs, bagging and cleaning out the Flaker. The average personal time weighted average exposure during normal conditions was 2.86 mg/m3 with a maximum value of 3.66. For personal job task samples, the average was 2.70 mg/m3 with the highest value being 11.05. During maximum normal conditions, the average personal job task exposure was 14.32 mg/m3 and ranged from 0.95 mg/m3 to 144.0 mg/m3 . Attached are two reports. The first is a summary document which gives the average, minimum and maximum exposure results by determination type and sample type for normal conditions. The second is a list of monitoring results by year for tetrathal. (Note: Condition A is normal condition; B is maximum, normal condition; and E is turnaround/infrequent maintenance. From a historical prospective, a major employee exposure reduction project was installed in 1979. It would be safe to assume that exposure prior to that time would have been higher than current levels. The plant is planning on developing a monitoring method which will be specific to tetrathal. Additional monitoring utilizing the new method is planned when the process is running again. JLW:kk Enclosure 7- J. L. Wolfsberger SU3J i t r -