Special Provision IP19 — 49 CFR 172.102 (IB-Codes and IP-Codes)

Code	IP19
Description	For UN identification numbers 3531, 3532, 3533, and 3534, IBCs must be designed and constructed to permit the release of gas or vapor to prevent a build-up of pressure that could rupture the IBCs in the event of loss of stabilization.
HazMat with this Code	UN 3532 - Polymerizing substance, liquid, stabilized, n.o.s. UN 3534 - Polymerizing substance, liquid, temperature controlled, n.o.s. UN 3531 - Polymerizing substance, solid, stabilized, n.o.s. UN 3533 - Polymerizing substance, solid, temperature controlled, n.o.s.