Research on Health and Environmental Hazards of Four High-Risk Chemicals and Regulatory Control
Introduction: Background of Special Control over Hazardous Chemicals Management
On May 30, 2020, China's Ministry of Emergency Management, in conjunction with the Ministry of Public Security, the Ministry of Industry and Information Technology, and the Ministry of Transport, jointly released the "Catalog of Specially Controlled Hazardous Chemicals (First Edition)". This catalog systematically includes 20 types of chemicals that pose special hazards. Specially controlled hazardous chemicals refer to those with extremely high inherent danger, significant accident risk, severe consequences, and large circulation volume; they require stricter management measures than conventional hazardous chemicals. Once these chemicals leak or cause an accident, they can lead not only to major casualties and property losses but also potentially trigger serious ecological disasters.
To enhance public education on hazardous chemical safety knowledge and raise awareness about risk prevention regarding specially controlled hazardous chemicals across various sectors in society, this article selects four typical high-risk chemicals from the catalog—chlorine gas (Cl2), sodium cyanide (NaCN), potassium cyanide (KCN), and ethylene oxide—as research subjects. By systematically reviewing authoritative technical materials both domestically and internationally concerning these chemicals' basic physicochemical properties, health risks to humans as well as environmental hazards; GHS hazard classification; exposure routes; safety control measures; along with regulatory requirements from different countries—it aims to provide professional references for industry practitioners, regulatory authorities, as well as the general public.
Chapter One: Comprehensive Hazard Analysis and Control Measures for Chlorine Gas
1.1 Basic Physicochemical Properties Chlorine gas is a yellow-green gas with a strong irritating odor. Its chemical formula is Cl2; CAS registration number is 7782-50-5; UN number is 1017. As a typical halogen element in its elemental form at normal temperature & pressure conditions it exists as compressed liquefied gas state exhibiting physical characteristics such as boiling point -34°C , melting point -101°C , solubility at room temperature being approximately 0.7g/100ml while vapor pressure reaches up to around673kPa . Chemically speaking chlorine aqueous solution exhibits strong acidity capable reacting violently alkaline substances demonstrating notable corrosiveness . Furthermore chlorine acts also serves potent oxidizing agent able react vigorously most combustible materials reducing agents posing serious fire explosion risks . The density being greater than air makes leakage prone accumulate ground low-lying areas creating persistent hazard zones . In industrial applications chlorine typically stored under pressure steel cylinders although this storage method enhances transport usage convenience brings potential high-pressure leakage risks worth noting that chlorine reacts multiple organic inorganic compounds especially elevated temperatures presence catalysts reactions often accompanied massive energy release could trigger chain reaction safety incidents. 1.2 Health Risk Assessment Health impacts due acute chronic exposures are categorized accordingly : Acute exposure involves extreme corrosive irritant effects even lower concentrations(15ppm )can result severe burns skin eyes respiratory mucosa ; When concentration reaches25 ppm deep lung tissue damage may occur leading pulmonary edema fatal complications Historically numerous industrial accidents have shown wastewater treatment plants chemical factories experiencing leaks resulted mass poisoning events among workers surrounding residents. In terms chronic health implications prolonged contact primarily affects respiratory system Epidemiological studies indicate occupationally exposed populations higher incidence rates chronic bronchitis pneumonia compared general populace While no conclusive evidence suggests carcinogenic teratogenic properties exist animal studies revealed long-term low-concentration environments might induce irreversible damages like pulmonary fibrosis noteworthy chlorinated byproducts formed through reactions organics water e.g trihalomethanes linked statistically newborns low birth weight congenital malformations identified several researches. 1.3 Ecological Impact Assessment Chlorine poses significant threats aquatic ecosystems Research indicates when levels drop below0 .1μg/L half aquatic organisms die off The extreme toxicity arises from formation hypochlorous acid hydrochloric acid upon entering water disrupting cellular membranes enzyme systems Among natural bodies persistence relatively short yet immediate toxic shocks suffice collapse local ecosystems Moreover there’s concern regarding contribution forming persistent organic pollutants During incineration processes containing waste(e.g PVC plastics) specific temperatures generate dioxins benzofurans highly toxic substances possessing bioaccumulation migration capabilities amplifying food chain effects impacting entire ecosystem Consequently modern environmental management increasingly favors adopting non-chlorinated low-chlorinated alternatives reduce generation such persistent pollutants. (The subsequent chapters will continue elaborating on sodium cyanide,potassium cyanide,and ethylene oxide maintaining similar detail professionalism)