Many materials in common use today have obvious reactivity hazards, for example, explosives, laboratory chemicals, and raw materials to make plastics and other useful products. Yet they are handled safely every day. How? Their hazards have been recognized and controlled so that undesirable events (those which can cause loss and harm) do not happen. Your first source of information for controlling hazards should always be your material supplier.
If you can eliminate the use of reactive materials, substitute materials with less reactivity potential, reduce inventories of materials, and/or reduce the severity of operating conditions, then you will be moving in the direction of an inherently safer operation. Be very careful that one hazard is not just substituted for another when making these kinds of changes.
Codes and Standards
Where some reactivity hazards have been handled for many years by companies in similar ways, industry codes and standards have been developed that specify needed safeguards. After your material supplier, these codes and standards should be your next point of reference for controlling hazards. For example, organic peroxides are commonly used as initiators and curing agents. If you handle organic peroxides, NFPA 432 (formerly NFPA 43B), Code for the Storage of Organic Peroxide Formulations, gives safe storage and handling considerations.
When reactivity hazards are unavoidable, multiple safeguards can be set up as lines of defense. These safeguards can prevent abnormal situations, keep abnormal situations from leading to incidents such as fires and explosions, and reduce the severity of consequences if an incident does occur. To be effective, safeguards, such as those listed below, must be carefully designed, properly installed, and maintained in working order throughout the lifetime of your facility.
- Train all personnel to be aware of reactivity hazards and incompatibilities and to know maximum storage temperatures and quantities
- Design storage and handling equipment with all compatible materials of construction
- Avoid heating coils, space heaters, and all other heat sources for thermally sensitive materials
- Avoid confinement when possible; otherwise, provide adequate emergency relief protection
- Avoid the possibility of pumping a liquid reactive material against a closed or plugged line
- Locate storage areas away from operating areas in secured and monitored locations
- Monitor material and building temperatures where feasible with high temperature alarms
- Clearly label and identify all reactive materials, and what must be avoided (e.g., heat, water)
- Positively segregate and separate incompatible materials using dedicated equipment if possible
- Use dedicated fittings and connections to avoid unloading a material to the wrong storage tank
- Rotate inventories for materials that can degrade or react over time
- Pay close attention to housekeeping and fire prevention around storage and handling areas
- Some operations will need to be contained within special blast-resistant enclosures
- Have an emergency response plan in place and conduct periodic drills
Each of these considerations will not, of course, apply to every material and situation. To look at your operation in a systematic, rigorous way with a knowledgeable group of people, a process hazard analysis can be conducted. Books and outside consulting resources are available that can provide guidance and professional assistance when needed.