Organic peroxide formulations are thermally unstable, which means they will self-react when exposed to certain temperatures. While some may be stored at normal ambient temperatures without any safety implications, others must be stored at cold temperatures. Following recommended storage and handling practices can effectively reduce the risks associated with handling organic peroxide formulations.
Hazards that may be associated with organic peroxide formulations include rapid decomposition due to high temperature or contamination with other chemicals, rapid burning and sensitivity to shock or friction, as well as potential human health hazards due to contact with eyes or skin or due to swallowing. Therefore, care is taken in classifying these formulations regarding storage and transportation.
Safe storage practices for organic peroxides prioritize incident prevention. Manufacturers of organic peroxides use strict safe handling procedures, which include storing organic peroxide formulations only in approved containers in well-ventilated areas, away from any sources of heat or flame and incompatible chemicals, and ensuring that these containers are kept at or below the maximum recommended storage temperature for the product.
Because organic peroxide formulations are thermally unstable, they must be stored at proper temperatures in accordance with the manufacturer’s instructions. Backup measures should be in place for organic peroxides that must be refrigerated in case the primary means of temperature control fails.
Certain organic peroxides are listed in Appendix A of the Process Safety Management (PSM) regulations (OSHA 1910.119), which is a List of Highly Hazardous Chemicals, Toxics and Reactives. (2) Facilities that store or handle these materials in quantities exceeding the threshold limits must follow PSM requirements.
The details of storage facilities and fire prevention and protection measures may be found by consulting with the manufacturers and by reviewing guidance documents such as the National Fire Protection Association (NFPA) guideline NFPA 400. (3)
Health and environmental impacts
Organic peroxides decompose to form byproducts that may include gases consisting of small hydrocarbons and in some cases carbon dioxide. These hydrocarbons normally burn off in any fire that results from the organic peroxide decomposition, but some may be carried up by plumes of smoke (soot) that may form due to incomplete combustion.
Some organic peroxide formulations include diluents intended either to reduce the hazards or make them easier to use. These diluents may include odorless mineral spirits, water, inert solids or even polymer carriers.
In occupational settings, direct exposure to organic peroxides may cause eye, skin and/or respiratory irritation, as well as nausea, drowsiness or dizziness. Typical protective equipment includes eye protection and chemical resistant gloves, but some formulations may require the use of respiratory protection, in the absence of engineering measures. Consult the manufacturer’s Safety Data Sheet (SDS) for the specific concerns and mitigation measures.
Organic peroxide formulations should be disposed as hazardous materials. They should not be discharged to sanitary sewers or discarded in the trash. (4)