In which the amount of formaldehyde should not exceed 10mg/kg a and volatiles 1. 5 % .There are many types of asphalt damping plates, including hot-melt, self-sticking and magnetic ones. In terms of source, there are coal-tar asphalt and petroleum one, among which the former is undoubtedly poisonous and harmful while the latter is less poisonous. What is terrible is not that cars employ asphalt damping plates, but that they use sub standard asphalt or even coal-tar asphalt which clearly cannot meet the requirements of vehicle production.
Furthermore, the petroleum asphalt used by many domestic companies of damping plates from oil fields like the one in Daqing is by no means non-toxic, because it is only relatively less poisonous. Based on the Cancer Hazard Ranking (2005) by IARC, coal-tar asphalt is classified as a Group 1 car Cinogen, whereas the gasification of asphalt and laborers direct contact with asphalt or its volatiles when paving a road are defined into Group 2B, substance which is “possibly carcinogenic without clear proof.”