Knowledge links
1、H.S. CODE: http://service.customs.gov.cn/default.aspx?tabid=9409
2、ChemBlink http://www.chemblink.com/indexC.htm
3、 http://cheman.chemnet.com/danger.html
4、MSDS: http://www.free-msds.net/index.php
5、World Ports: http://port.sol.com.cn