HazMat Tool — substance information Reference only — not a shipping paper, placard mandate, or CVI record.

Polymerizing substance, solid, stabilized, n.o.s.

HMT 15 June 2026
Reference only — HMT snapshot for inspection and audit support; not a shipping paper, placard mandate, or CVI record. Use Print / PDF below for field notes.
UN / ID
UN 3531
Hazard class
4.1
Packing group
III
ERG guide
ERG 149P
Special provisions
SP 387, SP IB7, SP IP19, SP N92, SP T7, SP TP4, SP TP6, SP TP33
Source
49 CFR §172 (15 June 2026)

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Polymerizing substance, solid, stabilized, n.o.s.


In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them. In chemical compounds, polymerization can occur via a variety of reaction mechanisms that vary in complexity due to the functional groups present in the reactants and their inherent steric effects. In more straightforward polymerizations, alkenes form polymers through relatively simple radical reactions; in contrast, reactions involving substitution at a carbonyl group require more complex synthesis due to the way in which reactants polymerize Wikipedia

Emergency Response Guide No. 149P

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

4.1
Flammable solids

(4) Identification number Help

UN 3531

(5) Packing Group Help

III

(6) Labels Help

Flammable solids (4.1)

(1) Symbols Help


This entry is signed with "G". The letter "G" identifies proper shipping names for which one or more technical names of the hazardous material must be entered in parentheses, in association with the basic description. (See §172.203(k)).

(7) Special Provisions (§172.102) Help

×Note:
Special provisions may be very complex. The extracts are taken from 49 CFR §172.102. Please be careful with the information, as necessary, additional conditions may be applied that are not written here. Please check the original source and report bugs.
387
IB7
IP19
N92
T7
TP4
TP6
TP33

(8) Packing Authorizations (§173.***) Help

(8A) ExceptionsNone
(8B) Non-bulk213see 49 CFR §173.213
(8C) Bulk240see 49 CFR §173.240

(9) Quantity Limits Help

(9A) Passenger aircraft/rail10 kg
(9B) Cargo aircraft only25 kg

(10) Vessel stowage Help

(10A) Location
(10B) Other

Segregation chart for load, transport, and storage

This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.

Prohibited Must not be loaded, transported, or stored together in the same vehicle or facility.
Permitted May be loaded, transported, or stored together.
Restricted May be loaded, transported, or stored together only with restrictions.