Home / Standards / GB/T 20020-2013 GB/T 20020-2013 Abolished Fumed silica 气相二氧化硅 Standard Type GBT ICS 83.040.20 CCS G49 Status 废止 Issue Date 2013-09-06 Implementation 2014-01-31 Responsible Dept 中国石油和化学工业联合会 Drafting Unit N/A