Peroxide flammability is quantified by both the flash point and the burn rate of the formulation. Most organic peroxides have flash points above 100 F (38 C) so they are typically not readily ignitable. However, many organic peroxides burn at a faster rate than common flammable and combustible liquids. For some peroxide formulations the burn rate is more than an order of magnitude faster than that of gasoline, which could result in more extensive damage to a storage building if ignited. For this reason, proper procedures must be in place and followed to prevent ignition, and operators must not become complacent about peroxide hazards, even after years of incident-free peroxide use. Standards issued by the National Fire Protection Association provide detailed recommendations for preventing fires in composites manufacturing facilities. Resin spray operations are covered in NFPA 33 and combustible dust from grinding operations in NFPA 652. Standards are available at catalog.nfpa.org.Contamination can also lead to incidents involving organic peroxides. Foreign materials like acids, bases, reducing agents and oxidizers – and common materials like metals and rust – can destabilize an organic peroxide so that it decomposes at temperatures at which it is normally stable. Organic peroxide users should refer to SDSs for the procedures that should be implemented to prevent contamination of organic peroxides by other substances and to quickly clean up spills of organic peroxides. Acidic absorbents should not be used for spill cleanup procedures. It is generally recommended that calcium carbonate be used as the absorbent for cleanup of organic peroxide spills.Shock sensitivity applies only to a few organic peroxides. None are in common use in the composites industry.In conclusion, organic peroxides are important additives for the composites industry due to their unique reactivity. However, these chemicals also have distinct hazards that must be managed through proper storage and handling procedures to minimize risk. Technical personnel at most organic peroxide suppliers can help users identify the appropriate organic peroxides to meet their technical needs and provide guidance to enable safe storage and use.
Peter Dluzneski, Ph.D., is a Senior Research Scientist at Arkema Inc. Email comments to peter.dluzneski@arkema.com.
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