Analysis of newly revised national standard for chemical protective clothing
Objective This paper aims to clarify the situation after the revision of the national standard for chemical protective clothing to enhance correct understanding the new specifications of chemical protective clothing.It is expected that this work will help engineers make scientific and reasonable selection of chemical protective clothing from the perspectives of protective performance and service performance based on the hazard degree of chemicals in different job sites,to ensure the personal health and life and property safety of users.Method During developing the new national standard of chemical protective clothing in China,references were made to some foreign standards of chemical protective clothing,including International Organization for Standardization(ISO),European Committee for Standardization(CEN)and National Fire Protection Association(NFPA).Focusing on the changes in the revised GB 24539-2021"Protective Clothing:Chemical Protective Clothing",this paper interprets the standard from the aspects of classification,performance requirements and test methods.Results It is found that GB 24539-2021 integrated GB 24539-2009"Protective Clothing:General Technical Requirements for Chemical Protective Clothing",GB 24540-2009"Protective Clothing:Chemical Protective Clothing against Acids and Alkalis"and GB/T 29511-2013"Protective clothing:Chemical Protective Clothing for Solid Particles",and the classification of chemical protective clothing was greatly adjusted and updated by deleting the non-airtight chemical protective clothing-ET,and by adding the airtight chemical protective clothing,limited liquid spray chemical protective clothing and woven material liquid acid and alkali chemical protective clothing.Accordingly,the performance requirements were also changed greatly,these mainly including the overall protective performance of clothing,the protective performance of clothing fabrics and the physical and chemical properties of clothing fabrics.Among them,liquid leakage performance in the overall protective performance of clothing was deleted,and inward leakage rate,limited liquid-tight spray performance and practical performance were added.New requirements for the protective performance of clothing fabrics were put forward in combination with various types of protective clothing which were reorganized.The grading indexes of wear resistance and flex resistance for physical and chemical properties of clothing fabrics were adjusted to better suit the actual situation of most protective clothing fabrics at present.Test methods in GB 24539-2021 mostly followed the test methods in the previous relevant standards,but they were also improved and perfected accordingly,including the sample pretreatment conditions and test environment conditions,the test method of inward leakage rate of chemical protective clothing,the test method of liquid tightness of chemical protective clothing,the test method of wear resistance of chemical protective clothing fabrics and the test method of bending resistance.Among them,the sample pretreatment conditions,and test environment conditions were added in the new revision which had not been unified and made clear in the previous standards.The test method of inward leakage rate of chemical protective clothing is a new content in this standard revision to evaluate the overall protective performance of airtight chemical protective clothing more comprehensively.The liquid tightness test of chemical protective clothing in the revised standard includes three test methods,which are respectively suitable for the liquid tightness test of jet liquid-tight chemical protective clothing,spray liquid-tight chemical protective clothing and limited liquid spray chemical protective clothing.As for the testing methods for abrasion resistance and flex resistance of chemical protective clothing fabrics,the qualitative evaluation method of visual observation was improved and two quantitative evaluation methods,i.e.,the pressure tank method and hydrostatic pressure method,were added.Conclusion The revised national standard of chemical protective clothing will play an important role in promoting market development,improving product quality,and protecting users′personal health and life safety.
national standardprotective clothingchemical protective clothingprotective performancewear resistance