The objective of this project is to survey the current exposure level of BTEX to laboratory technicians by measuring intake and their metabolites in urine sample. It is also to take appropriate actions to control their exposure through improvement in facility, practices and corrective actions.
Occupational health survey on technicians performing sampling and analysis of crude oil, condensate, paraffinic naphtha etc. was carried out every year by a competent external agency. The BTEX vapors were absorbed in a passive sampler for 8 hours held close in the breathing zone of technicians. The absorbed components were extracted and analyzed using chromatograph for benzene, toluene, ethylbenzene and xylene. Their metabolites were determined by collecting pre/post urine samples after extended hours of exposure.
In 2010 BTEX were below the threshold and detection limits in 4 cases out of 5. The BTEX metabolites were below detection limit (DL) and Threshold Limit value (TLV). In Oct 2012, the survey indicated abnormal and higher BTEX values; particularly Toluene was 120 mg/m3 as against the TLV of 75 mg/m3. Several steps were taken which included training, awareness of technicians, good laboratory practices, personal protective equipment and improved exhaust system and ventilation. The air intake velocity of fume hoods, HVAC system, the ambient temperature etc. were inspected and monitored. Additional fume hood was installed to extract vapors. The activated carbon filters of all 19 air extraction blowers were replaced in Sep-2013 to ensure increase in fume hood air velocity and for complete absorption of BTEX in these filters so that there is no air pollution.
A special type of face mask (Model 3M 9922) was introduced which prevents direct inhalation of volatiles. BTEX exposure was minimized by improving the performance of fume hoods, extraction system, exhaust bowers and HVAC Units. Training of technicians and their awareness on release of BTEX and ways of minimizing their exposure helped us to implement a good laboratory practice thereby minimizing exposure. Strict adherence to safety procedures and using appropriate personal protective equipment reduces inhalation of BTEX. Improvement in the exhaust filters minimized air pollution. The subsequent surveys indicated that the working place is well protected against release of BTEX and there is no risk to health of the staff. By the whole process we could meet both local and international legislation on BTEX emissions.
This significant improvement can be shared with ADNOC group of companies having similar work place hazards. This can be considered as an achievement and operational excellence towards ADGAS commitment in safeguarding the safety of our employees and looking for improving the work environment.