Determination Methods And Occupational Exposure Limits For DMP And DEP In The Air Of Workplace

【Objective】To establish the sampling,processing and determination methods of dimethyl phthalate and diethyl phthalate in the air of the workplace,and put forward the suggestion of occupation exposure limits.【Methods】1.In this study,the dimethyl phthalate and diethyl phthalate in the air of the workplace were determined by gas chromatograph combining with flame ionization detector after fiber glass filter membrane sampling,toluene elution and HP-1 gas chromatography separation.2.In order to understand the relationship between exposure of dimethyl phthalate and diethyl phthalate in the air of the workplace and occupational health injury of workers,we selected the production and use enterprises to conduct on-site occupational hygiene survey to identify the major exposure post,worker and pathway,etc.Then the dimethyl phthalate and diethyl phthalate levels in the workplace air and individual exposure level were determined using fixed-point and individual sampling.At the same time,the data of workers’basic information and past occupational health status were collected by questionnaire and occupational health checkup.The results of the basic information,past occupational health status and occupational health checkup in the exposure and control groups workers were statistically analyzed by Chi-Square test.Combined with the GBZ/T 210.1-2008 and foreign occupational exposure limits for dimethyl phthalate and diethyl phthalate in the workplace air,we proposed occupational exposure limits for dimethyl phthalate and diethyl phthalate in workplace air of our country on the basis of physical and chemical properties of dimethyl phthalate and diethyl phthalate,production and use status,metabolism,excretion and toxicity,etc.【Results】1.The methods for dimethyl phthalate and diethyl phthalate determination in the workplace air.The results showed that dimethyl phthalate has a good linearity in the concentration range at 14.0-1400.0μg/ml,the correlation coefficient was 0.999 98,detection limit was 1.27μg/ml,minimum detected concentration was 0.141mg/m~3(with 45L air samples),within-run precision was 1.21%~1.94%,between-run precision was 1.22%~2.51%,spike recovery rate was 96.55%~97.30%,sampling and desorption efficiencies were separately 100.0%and94.82%~98.08%.The sample could be stored for 15 days under sealed and dark conditions(the sample descend rate was lower than 10%).The results showed that diethyl phthalate has a good linearity in the concentration range at 14.0-1400.0μg/ml,the correlation coefficient was 0.999 99,detection limit was 1.10μg/ml,minimum detected concentration was 0.122mg/m~3(with 45L air samples),within-run precision was 1.04%~2.75%,between-run precision was 1.61%~3.09%,spike recovery rate was 98.72%~103.21%,sampling and desorption efficiencies were separately 100.0%and97.25%~98.68%.The sample could be stored for 15 days under sealed and dark conditions(the sample descend rate was lower than 10%).2.The occupational exposure limits for dimethyl phthalate and diethyl phthalate determination in the workplace air.According to the on-site occupational hygiene survey,different concentrations of dimethyl phthalate and diethyl phthalate were widely distributed in the production enterprises posts of raw material throwing,synthesising,neutralization,washing,dehydration,rectification,fractionation,packaging,storage,and using enterprises posts of raw material throwing,reaction and storage,rest area etc.The concentration of“packaging”in production enterprises was highest(dimethyl phthalate:0.85~1.13mg/m~3;diethyl phthalate:0.83~1.16mg/m~3),and the concentration of“raw material throwing”in the enterprise was highest(dimethyl phthalate:0.97~1.21mg/m~3;diethyl phthalate:1.06~1.27mg/m~3).On the basis of no statistical difference between the basic informmation of exposure group and control group,the past health status were analysised by Chi-Square test.In the dimethyl phthalate exposure group of 46 people,5 people reported headache,dizziness,eye discomfort and other discomfort symptoms;however,in the dimethyl phthalate control group of 39 people,3people reported headache,dizziness,cough and other discomfort symptoms.In the diethyl phthalate exposure group of 41 people,7 people reported headache,dizziness,eye discomfort and other discomfort symptoms;however,in the diethyl phthalate control group of 37 people,4 people reported headache,dizziness,vomit and other discomfort symptoms.There were no statiscally differences between the past occupational health status in dimethyl phthalate and diethyl phthalate exposure group and control group(P>0.05).Moreover,the occupational health examination result in the dimethyl phthalate and diethyl phthalate exposure group and control group were analysised by Chi-Square test.In the dimethyl phthalate exposure group,there were 7 people abnormal health examination result;however,there were 3 people abnormal health examination result in the dimethyl phthalate control group.In the diethyl phthalate exposure group,there were 8 people abnormal health examination result;however,there were 3 people abnormal health examination result in the dimethyl phthalate control group.There were no statiscally differences between the occupational health examination result in dimethyl phthalate and diethyl phthalate exposure group and control group(P>0.05).In this study,the on-site occupational hygiene survey,past occupational health status analysis and occupational health examination did not find any harmful impact on workers’health caused by dimethyl phthalate and diethyl phthalate exposure.The American National Institute for Occupational Safety and Health and government industrial hygienist stipulate that the permissible concentration-time weighted average in the workplace air is 5mg/m~3.There were no dimethyl phthalate and diethyl phthalate occupational health hazard reports since yet.【Conclusion】1.The performance indexs of determination methods established in this study were corresponding with the“GBZ/T 210.4-2008”requirements,which was the guidelines for the occupational health standards formulation:part 4:chemical substances determination methods in the workplace air.After field test verification,they could be applied to the determination of dimethyl phthalate and diethyl phthalate in the workplace air.2.According to the on-site occupational hygiene survey,on-site concentration determination,questionnaires,past occupational health status data analysis and occupational health checkups in dimethyl phthalate and diethyl phthalate production and use enterprises,the workplace air dimethyl phthalate and diethyl phthalate permissible concentration-time weighted average in our country were set at 5mg/m~3 based on the occupational limits established by NIOSH and ACGIH.