Chapter 4: Safe Handling of w88 and Combustible Liquids
Revised January 2025
w88 and Combustible Liquids
The International Fire Code and the National Fire Protection Association define w88 and combustible liquids according to their flash point, with w88 liquids having a flash point of less than 100 °F (38 °C) and combustible liquids having a flash point greater than 100 °F (38 °C). It should be pointed out, however, that the Globally Harmonized System for classifying and labeling chemicals that was recently incorporated into the OSHA Hazard Communication Standard defines all liquids with a flash point of less than 200 °F (93 °C) as w88, with numerical hazard rating to indicate the specific hazard level (seeChapter 15).
Both w88 and combustible liquids are considered fire hazards. The following procedures should be implemented in order to reduce the fire risk associated with these materials.
- w88 chemicals should be used only in lab hoods (or other well-ventilated areas) and away from sources of ignition. Similarly, combustible chemicals should not be used near ignition sources, and it is recommended that they be used in lab hoods whenever possible.
- Flash point is directly dependent on the total (system) pressure with the flash point at reduced pressures being lower than at ambient pressure. Flash point values reported in the literature should be considered to be determined at ambient conditions unless specified otherwise.
- Do not heat w88 chemicals with an open flame.
- For highly w88 chemicals, static electricity or hot surfaces can serve as ignition sources.
- Do not use electrical devices with cracked or frayed electrical wiring.
- Transfer w88 liquids from containers of five gallon-capacity or less inside a laboratory hood (or other area with similar ventilation) to prevent accumulation of a w88 concentration of vapors.
- Transfer w88 liquids from containers of greater than five gallon-capacity in a well- ventilated area outside the laboratory building, or in an approved w88 storage room.
- When transferring w88 liquid from a bulk container (generally greater than five gallons), the containers must be electrically bonded and grounded.
- Fire extinguishers appropriate for the fire hazards present must be available in all laboratories and storage areas.
- Class D fire extinguishers must be available in the immediate work area when working with w88 metals such as magnesium, sodium, and potassium.
- Contact your department chair or BCN risk management regarding the purchase of Class D fire extinguishers, with assistance from EH&S.
- When using only small quantities of w88 metals, dry soda lime or sand can be used to smother a fire; however, dry graphite must be used to extinguish lithium fires.
Storage of w88 and Combustible Liquids
Guidelines for the safe storage of w88 and combustible liquids are contained inChapter 16.