Research On The Health Standard For Terephthalic Acid In The Ambient Air Of Workplace

Objective:To study the health standard for terepththalic acid(TPA) in the ambient air of workplace.Methods :Based on the physical and chemical property of TPA,toxicological studies,occupational health investigation and epidemiological study in the exposure workers,especially on the dose-response,exposure and level-response relationships and the lowest-observed-adverse-effect level(LOAEL) or non-observed-adverse-effect level(NOAEL),the health standard of TPA will be formulated after referencing to the foreign helth standard of TPA and the practical condition of this country.Results:TPA LD50 was more than 15000mg/kgbw. LOAEL was 40mg/kgbw through the subchronic toxicity study by oral administration of TPA. NOAEL was 8.93mg/m3 by the subchronic respiratory toxicity study. The genitic toxicity of TPA showed negative reaction based on Ames test ,bone marrow micronucleus test in Kunming mouse and mutagenictest.The occupational environmental monitoring of TPA showed that the concentration of area sampling ranged from 0.41 to 9.96mg/m3 and the time weighted geometric average concentration of TPA measured by personal sampling varied between 2.19 and 62.68 mg/m3.There was a correlative relationship between the concentration of TPA,measured by personal sampling,and that of urinary TPA.The occuptional survey and biological monitoring showed that urinary NH4T, |3 2-MG and serum SACE were significantly increased while serum UA was decreased when urinary TPA exceeded 5mmol/molCr. The exposure limit value of occuptional workers was suggested as 4.8mg/m3 according to the changes in renal function and blood biochemistry.Based on the result of lung function analysis,using life table method,an exposure limit of TPA dust was proposed to be 4.30 mg/m3.Conclusions:The maximum allowable concentration (MAC) and the time-weighted-average(TWA) allowable concentration wererecommended respectively as 15mg/mJ and 8mg/m based on the results of present studies.