Research on the standard limits for vinyl chloride and trichloroethylene in the "Standards for Drinking Water Quality（GB5749-2022）" in China / 中华预防医学杂志

The usage of vinyl chloride and trichloroethylene in China has been increasing year by year, and they have been detected in both drinking water and environmental water, making them important environmental pollutants. Based on the latest research results on the health effects of vinyl chloride and trichloroethylene, the newly issued, "Standards for Drinking Water Quality (GB5749-2022)" in China has adjusted the standard limit of vinyl chloride from 0.005 mg/L to 0.001 mg/L and the standard limit of trichloroethylene from 0.07 mg/L to 0.02 mg/L. This article analyzed and discussed the relevant technical contents for determining the above standard limits, including the levels and exposure conditions of vinyl chloride and trichloroethylene in the water environment, health effects, derivation of safety reference values, and determination of hygiene standard limits. Suggestions were also made for the implementation of this standard.

Development of a modified method for the simultaneous determination of vinyl chloride monomer and ethylene dichloride in the air

A commercial grade activated carbon has been used as an adsorbent medium. It has been loaded via a simple device with different mixtures of vinyl chloride and ethylene dichloride each administered separately. About 3 g of loaded active carbon is put in a vacutainer tube while 10 ml of technical grade CS2 as adsorbent is added. The tube is stoppered and stored at 4C. After 24 hours, 1 ml aliquot is injected through a closed loop to a precalibrated infrared gas analyzer to assess the percentage recovery of vinyl chloride and ethylene dichloride. The spent activated carbon is washed thoroughly with water and is dried in two stages [at 50C for 8 hours and at 120C for 16 hours] to be used again. The procedure is accurate, precise, simple and economic. It gave percentage recoveries of 85% for VCM and 100% for EDC. It depends on the available resources, making it a suitable methodology to be applied in a developing country

Performance of a modified method for the simultaneous determination of vinyl chloride monomer and ethylene dichloride in the atmosphere of a petrochemical plant in Alexandria

Ethylene dichloride [EDC] and vinyl chloride monomer [VCM] are considered the major air pollutants associated with any petrochemical industry. The two pollutants are categorized as carcinogenic substances for man and animal. Large number of samples were collected from the air of a Petrochemical Plant in Alexandria during a period of 12 months to study the efficiency, accuracy and applicability of a modified method for the simultaneous determination of VCM and EDC in the air. For this purpose, different sampling stations were selected inside the plant and at its walls. Samples of VCM and EDC were collected simultaneously by adsorption on the surface of activated charcoal and then analyzed by a chemical desorption process using carbon disulfide [CS2]. Levels of VCM and EDC were determined by an infrared spectrophotometer