Vents in DOT Specification 34 Polyethylene Drums

This is in response to your letter requesting a written clarification on the use of vents in DOT Specification 34 polyethylene drums, 6D overpacks with plastic containers, and tote bins for shipments of Ammonium hydroxide. I apologize for the delay in responding and hope-it has not caused you any inconvenience.

The Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180), as revised in the December 21, 1990 final rule under Docket HM-181, contain provisions for the venting of packagings in 49 CFR 173.24(g). Venting of packagings to reduce internal pressure which may develop from the evolution of gas from the contents is permitted only under very limited conditions. Vented packages may not be transported by air. If the evolved gas is poisonous, creates a flammable mixture with air or is an asphyxiant under normal conditions of transportation, venting is not allowed. It is a shipper's responsibility to determine whether the evolved gas poses such a hazard. Further, it is the shipper's responsibility to ensure that the packaging is designed to prevent an unintentional release of the material from the package. Therefore, you may use a vented packaging provided that: (1) your hazardous material is not transported by air; (2) any evolved gas from the hazardous material is not poisonous, flammable when mixed with air, or an asphyxiant; and (3) the packaging is designed to prevent an unintentional release.

I hope this information is helpful. Please contact this office if you need additional assistance.