Flammable solvents, management

Disposal is most difficult for the very small amount of chemical-biological waste that is EPA-regulated as chemically hazardous or contains a chemical, such as lead, that is inappropriate for an animal or medical waste incinerator. Disposal of tissue specimens preserved in ethanol or another flammable solvent is also difficult. In most cases, storage of this waste is limited to 90 days and must be managed at an EPA-permitted chemical waste facility. However, few chemical waste facilities are prepared to handle waste that is putrescible, infectious, or biohazardous. 

Brief Description of Incident This facility manufactured powder coatings and paint additives by a process using free-radical polymerization of acrylic monomers in flammable solvents. A customer requested more of an additive than the facility would normally make in a single batch, so managers decided to scale up the operation to produce the required amount for the order. The managers and most operators in this plant had been with the plant less than a year, and none of them had previous experience in manufacturing polymers. 

The process of risk management is sometimes easy and sometimes difficult and problematic. It is easy to wear personal protective equipment, such as safety goggles, and to take steps such as not using flammable solvents near ignition sources. The severity of a hazard is dependent not only on its nature but... 

Process Safety Management (PSM) Standard (29 CFR 1910.119) PSM is for the prevention or minimization of the consequences of catastrophic releases of toxic, reactive, flammable, or explosive chemicals. This regulation applies to all processes that involve one or more of 137 listed chemicals (29 CFR 1910.119, Appendix A) above their threshold quantities or have 10,000 lbs. or more of a flammable liquid or gas, as defined by the U.S. OSHA HCS [29 CFR 1910.1200(c)], This includes n-hexane, hexane isomers, and all solvents listed in Table 14.10.3. 

The major disadvantages of solvent-based adhesives, and the issues triggering their replacement, are regulatory restrictions on solvent emissions, waste disposal, and factory vapor levels. Many solvent systems are also flammable and require safety and health-management processes. 

Many of the commonly used solvents are volatile organic compounds (VOCs), hazardous air pollutants (HAPs), flammable, and/or toxic. They also pose serious environmental, health, and safety (EHS) concerns, including human and eco-toxicity issues, process safety hazards, and waste management issues. 

Although the base solvents found in semi-aqueous solvent mixtmes are normally of low volatility, flammability of aerosols is an issue. Solvent-air aerosols are created by expansion of emulsion through pressurized nozzles into air. Consequently, the emulsion vessel must be managed to safely contain flammable materials. The presence of water does not innoculate against this hazard . 

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