At the request of a customer that ships materials poisonous by inhalation (TIH drums, formerly known as PIH), we have researched and learned that the performance criteria of cap seals on these steel drums needs to be qualified by each shipper, not the cap seal manufacturer. As required in 49CFR 173.226(b)(3)(iii), a cap seal is required to withstand 100 kPa as a primary seal – not in conjunction with the inner plug. There are two predominant manufacturers of these cap seals (Rieke and American Flange) and both are unwilling to issue performance certification for their cap seals as a primary seal. While they are offering a 100 kPa certification that includes the installed plug, this is not compliant with the CFR. While DOT is aware of this issue, we are suggesting to all TIH shippers that they perform their own performance test to certify that the cap seals, when installed as the primary seal, are able to meet the 100 kPa criteria. If inspected by DOT, failure to have this information documented could lead to a finding of non-compliance.
DOT/UN Industry News Safety