Preliminary Study On The Release Limit Of Volatile Organic Compounds In Wood-Based Panels

With the improvement of people's living standards and environmental awareness,indoor air quality has received more and more attention from the public.Since people's daily life and main activities are carried out indoors,which make people spend most of their time indoors,so indoor air quality is closely related to people's health.With the increasing popularity of wood-based panels and their products in interior decoration,the volatile organic compounds from them has become a major source of indoor air pollution.In order to control the concentration of harmful substances and improve indoor air quality,many countries in Europe and America have established various standards for limiting the release of volatile organic compounds.However,China started late in this respect and there are no systematic relevant standards.Therefore,the development of volatile organic compound release limits for wood-based panels is of great significance for improving indoor air quality and ensuring the health of citizens.This paper initially explored the release limit of volatile organic compounds in wood-based panels.By analyzing and summarizing relevant standards at home and abroad,theoretical basis was provided.The lm3 chamber was used to test the VOCs release level of wood-based panels in market.The concentration and types of VOCs were qualitatively and quantitatively analyzed by GC/MS.The comprehensive index evaluation method was used to evaluate the influence of the release of VOCs on the indoor air quality based on the pre-established limit value,and compared with the evaluation results based on the standard made by Bernd.Conclusions were as follow:(1)By analyzing the characteristics of existing relevant standards at home and abroad,the development of this standard referred to the UL GREENGUARD.This standard divided the wood-based panels into qualified products and superior products,and specified that the concentration of specific VOCs,such as benzene,toluene,xylene,ethylbenzene,biphenyl,naphthalene,styrene,released by superior products shall not be higher than TLV 1/100,or no more than half of the CRELs value.In addition,the concentration of total volatile organic compound(TVOC),total aldehydes,and other VOCs monomer were also limited.(2)Through experiments,the law is as follows:?The TVOC concentration of different wood-based panels had the same trend.The concentration of TVOC decreased with time.The TVOC concentration released by the wood-based panels in the market under steady state was less than the established limit,reaching the level of superior products.After surface decoration,the concentrations of TVOC released by the wood-based panels were different,which because the sealing ratio of VOCs was different for different facing materials.PVC material had the best sealing effect on VOCs,followed by melamine impregnated film paper,while acrylic water-based paint would release a lot of volatiles,increasing the release of VOCs.?The change in TVOC concentration was mainly caused by the main substances released from wood-based panel.At the initial stage of release,the concentration of the main substance was high,which increased the release concentration of TVOC.The main release material had a similar concentration trend as TVOC.Therefore,in the process of controlling volatile organic compounds in wood-based panels,the most important thing is to control and inhibit the release of major substances of VOCs at the initial stage of release.?In the equilibrium state,the concentration of aromatic hydrocarbons in volatile organic compounds released from wood-based panels was the highest.Benzene,toluene,biphenyl,naphthalene and other aromatic hydrocarbon monomers were the main limiting substances.According to the World Health Organization's toxicity classification of foreign compounds,the toxicity of the main volatile organic compounds released from the wood-based panels under equilibrium was analyzed.In the equilibrium state,particleboard mainly released five kinds of aromatic hydrocarbons and two kinds of esters.Among the seven substances,the most toxic was naphthalene and dibutyl phthalate.In the steady state,the plywood released 11 kinds of aromatic hydrocarbon monomers,among which the highest toxicity was naphthalene,the lowest toxicity was para-xylene,and the other 9 monomers were low toxicity.In the steady state,the MDF releases 12 kinds of aromatic hydrocarbon monomers,which were benzene,ethylbenzene,1-methylene-hydrazine,1-methylnaphthalene,biphenyl,2-methylnaphthalene,anthracene,phenanthrene,and Xylene,toluene,naphthalene,anthracene.Among the 12 volatiles,naphthalene and anthracene had the highest toxicity.The toxicity of p-xylene was the lowest,which was slightly toxic,and other substances were low toxicity.?Applying the comprehensive index evaluation method to evaluate the influence of the release of VOCs on the indoor air quality by two different standards.It was found that the volatile organic compounds released from the wood-based panels at the initial stage of release had a greater impact on indoor air quality.It was recommended that the panels should be placed for at least 28 days before using them.By comparing the evaluation results,it was found that there was good correlation between the two evaluation results,indicating that the proposed guidance value for the release of volatile organic compounds in wood-based panels was feasible.