Occupational Exposure Limit And Determination For Decabromodiphenyl Ether In The Air Of Workplace

Decabromodiphenyl ether (DecaBDE) is the most commonly used bromide flameretardants which is added to the electronical applications and to improve their fireresistance. DecaBDE has been a persistent organic pollutants for decades. It casues globalenvironmental pollution after using as industrial raw materials. Because of the pollution ofDecaBDE, the EU and North America countries have banned the use of DecaBDE. Theproduction and sale of DecaBDe moved to our country in recent years. It was reported thatChina has become emerging markets for DecaBDE. The production capacity of DecaBDEhas reached50,000tons in our country in2006, which accounted for25%the world’s totalconsumption. During the products including DecaBDE are produced, used, dismantled orburned, DecaBDE can be released and stay in the air of workplaces. If workers are exposedto DecaBDE for a long time, DecaBDE could be absorbed and accumulated in body, andeventually leads to health damage. Till now, there is no occupational exposure limit forDecaBDE and no standard method to determine this substance in workplaces. In order toprevent adverse health effects from DecaBDE in workplace, we explored the exposure limitand determining method for DecaBDE through literature review and field investigations inthis study. There are two parts in the study. Part1Occupational exposure limit for decabromodiphenyl ether inthe air of workplaceDecabromodiphenyl ether (DecaBDE) is white solid, CAS:1163-19-5, molecularormula:C12Br10O, molecular weight:959.17, solution point:300~310℃, boilingoint:320℃,21℃steam pressure (Pa):4.63x10-6, and slightly soluble in halogenatedydrocarbon, not soluble in water, alcohol, ether, ketone and other solvents,25℃ater-soluble <0.1μg/L. DecaBDE is mainly added to the electrical and electronics, plasticsextile, chemical, building materials and other synthetic materials to improve their fireerformance. When these products are processed, used, disposal of dismantled or burned,ecaBDE can be released to the air and enter the workers’ bodies through the skin orespiratory pathway.DecaBDE is mainly characterized by sub-chronic and chronic toxicity. Animalxperiments showed that DecaBDE has liver toxicity, endocrine disturbance toxicity,eproductive and development toxicity, and is carcinogenic. The Agency for Toxicubstances and Disease Registry (ATSDR) and Environmental Protection Agency (EPA)ormulate the minimum level of risk and reference dose (RfD) of DecaBDE as0mg/kg/day (sub-chronic oral exposurelevel) and0.007mg/kg/day according to the nobserved adverse effect level (NOAEL) in chronic and sub-chronic animal testing, as wells the observed neurobehavioral effects of the lowest observed adverse effectevel(LOAEL).The studies of adverse health effects of DecaBDE on exposed workers are relativelyimited. At present, no special diseases caused from DecaBDE were reported amongxposed workers. in occupational epidemiological studies.The level of DecaBDE in workplace is much higher than the level of surroundingnvironment, ranged from a few dozen to several thousand times higher than that in the environment. The high DecaBDE exposure occupations are e-waste dismantling, circuitboard assembly, rubber production, solid waste incineration, especially electronic wasterecycling plant. DecaBDE can be detected in biological samples such as blood, breast milk,fat or hair. DecaBDE levels of exposed workers are several tens to several hundreds timeshigher than those in general population. When DecaBDE was degradated as other polybrominated diphenyl ethers in environmental or through biological metabolism, whichcan affect the baby’s growth and development, adult’s reproductive system and endocrinesystems.Currently, the American Industrial Hygiene Association (AIHA) suggested thatoccupational exposure limit for DecaBDE in workplace air are5mg/m3(TWA). This limitvalue is adopted by many large companies’ Material Safety Data Sheet (MSDS). Toevaluate DecaBDE levels of workplace in our country, we chosed three typical plants amddetermined DecaBDE concentrations in the air of workplaces. The results showed thathighest concentration of DecaBDE was in production plant, reaching to0.44mg/m3.According to DecaBDE toxicity test data and population based epidemiological studies,considered actual production conditionsy, we recommend that PermissibleConcentration-Time Weighted Average (PC-TWA) of DecaBDE is5mg/m3in our country.Part2The method to determine decabromodiphenyl ether in the airof workplaceThere is no standard method to determine DecaBDE in workplace in our country. Inthis part, we explored to determine DecaBDE in workplaces through literature andlaboratory tests.The ultra-fine glass fiber filter were used to collect DecaBDE samples in the air ofworkplace. Then the samples were kept in cold and dark contidion and transported to the laboratory. The filter samples were added13C12-DecaBDE as internal standard, and then putin Soxhlet extraction for18~24h. The extractions were concentrated to near dryness byrotary evaporator. After that, use n-hexane to dissolve it and concentrated again. The solidphase silica extraction column (SPE) is purified concentrate, and eluent is concentrated bythe rotary evaporator, and then transferred to auto-sampler bottles, which are blown to neardryness with nitrogen. Finally, the concentrate is volume to0.5mL with toluene, and gaschromatography/mass spectrometry spectrometer (GC/MS) is used to determinate theDecaBDE. We used qualitative ions and retention time to qualitative and quantitative peakarea in the isotope internal standard.This method has a good recovery and precision. In the spiked concentration of50ng/mL,150ng/mL,500ng/mL level of the average recovery of86.23%to93.68%,intra-assay and inter precision were1.70%~4.41%and2.98%~5.01%. Elution efficiencytest average of91.72%and RSD is5.48%. The detection limit of this method is2.5ng/mLand3.3ng/m3when collected75L air sample count. We determined DecaBDE in theworksite in the three companies. The results showed that DecaBDE concentrations rangedfrom0.2ng/m3~443475ng/m3, with an average concentration of5505ng/m3. In conclusion,this method is appropriate for DecaBDE determination in workplace.