B. The organic peroxides that fall under NFPA classes I, II, and III are required to be labeled
with a DOT "ORGANIC PEROXIDE" label (UN Class 5.2) for transportation purposes, which
also facilitates directing them to type P storage. Classes IV and V may or may not be identified
with the DOT "ORGANIC PEROXIDE" label.
C. Hazard Considerations.
1. Class I organic peroxide formulations present a hazard through easily initiated, rapid,
explosive decomposition. Class I may include formulations that are relatively safe only under
closely controlled temperatures. Excessively high or low temperatures may increase the potential
for severe explosive decomposition.
2. Class II organic peroxide formulations present a severe fire hazard similar to that presented
by NFPA class I flammable liquids; however, the decomposition is not as rapid, violent, or
complete as that produced by class I formulations. As with class I formulations, this class may
include formulations that are relatively safe under controlled temperatures or when diluted.
3. Class III organic peroxide formulations present a fire hazard similar to NFPA class II
combustible liquids. They are characterized by rapid burning and high heat liberation, due to
4. All organic peroxide formulations are incompatible with strong acids, strong alkalis, strong
oxidizers, acetone, transition metal salts, promoters, and reducing agents.
D. Basic Requirements. Detached organic peroxide storage areas within general purpose
warehouses modified for the storage of organic peroxides should include the protective features
for hazardous materials storage identified in the reference cited in paragraph 4.7 with additional
consideration given to:
1. All storage areas containing organic peroxide formulations should be conspicuously
identified by the words "ORGANIC PEROXIDE" (SF 443 or DOT placards are acceptable) and
by class, and if more than one class is stored in the same area, then it should be marked for the
most severe class present.
2. Packages containing organic peroxides requiring temperature control should be marked
with the recommended storage temperature range, and they should be stored in an environment
within that range (i.e., refrigerated).
E. Applicable HCCs. The following HCC should be stored in storage type P:
1. P1, Peroxide, Organic, DOT regulated, NFPA classes I, II, and III.
2. P2, Peroxide, Organic, Low Risk, NFPA classes IV and V.