This standard specifies a method of measuring the concentration of volatile organic compounds (VOC) emitted from auto parts in order to reduce in-cabin VOC. Of substances listed as interior air contaminants in the guideline designated by Ministry of Health@ Labor and Welfare@ subject to this standard are TVOC and eight substances: formaldehyde@ acetaldehyde@ toluene@ xylene@ ethyl benzene@ styrene@ tetradecane and p-dichlorobenzene@ dibutyl phthalate@ Di(2-ethylhexyl) phthalate. Further dibutyl phthalate and Di(2-ethylhexyl) phthalate are applied to only parts of buses