CONTROL PROCEDURES FOR FLAMMABLE AND COMBUSTIBLE LIQUIDS

Flammable and combustible chemicals include liquids such as organic solvents, oils, greases, tars, oil base paints, and lacquers, as well as flammable gases. Flammable gases are discussed in PUB-3000, Chapters 7, “Pressure Safety and Cryogenics” and Chapter 13, “Gases.” The emphasis of this section is on flammable and combustible liquids.

Flammable and combustible liquids are defined by their flash points. The flash point of a liquid is the minimum temperature at which it gives off sufficient vapor to form an ignitable mixture with the air near its surface or within its containment vessel.  A liquid’s flash point is a function of its vapor pressure and boiling point.  Generally, the higher the vapor pressure and the lower the boiling point of a liquid, the lower its flash point will be.  The lower the flash point, the greater the fire and explosion hazard

Flammable and combustible liquids are classified by the National Fire Protection Association (NFPA) based on their flash points:

Flammable Liquids (Class I):  Liquids with flash points below 100°F (37.8°C) and vapor pressures not exceeding 40 pounds per square inch (absolute) at 100°F (37.8°C).  Flammable Class I liquids are subdivided as follows:

• Class IA: Liquids having flash points below 73°F (22.8°C) and boiling points below 100°F (37.8°C). Flammable aerosols (spray cans) are included in Class IA.
• Class IB:  Liquids having flash points below 73°F (22.8°C) and having boiling points at or above 100°F (37.8°C).
• Class IC:  Liquids having flash points at or above 73°F (22.8°C) and below 100°F (37.8°C).  The boiling point is not considered.

Combustible Liquids (Classes II and III):  Liquids having flash points at or above 100°F (37.8°C).  Combustible liquids in Classes II and III are subdivided as follows:

• Class II:  Liquids having flash points at or above 100°F (37.8°C) and below 140°F (60.0°C).
• Class IIIA:  Liquids having flash points at or above 140°F (60.0°C) and below 200°F (93.4°C).
• Class IIIB:  Liquids having flash points at or above 200°F (93.4°C).
  

Control Measures

• Work Leads are responsible for identifying flammable and combustible liquids used in the work area.  Review MSDSs for specific compounds. 
• An assessment of the hazards and controls in place is necessary to limit employee exposures to these agents.   Contact an EH&S Industrial Hygienist  to provide assistance.
• Some operations involving flammable and combustible liquids may require an Activity Hazard Document (AHD).   This is determined by the using Division in accordance with the provisions in PUB-3000, Chapter 6, “Safe Work Authorizations.”

Training and Information

• Employees who either handle or who may be exposed to flammable and combustible liquids are required to complete Chemical Hygiene and Safety Training, EHS 348 (or 345 for Facilities personnel or 352 for summer students). 
• All employees in the work area must be trained in the specific hazards and controls of the materials being handled. Area-specific training is a line management responsibility.  EH&S Industrial Hygienists are available to provide assistance.
• Primary and secondary containers must be labeled with the identity of the substance and its hazards. 
• The entrance to the work area should be posted with a Caution Placard depicting hazards and emergency contact information.

Substitution and Chemical Inventory Management

• Identify and use safer chemical alternatives (e.g., materials with higher flashpoints and higher boiling points) if possible.
• If a safer chemical can’t be used then limit what you buy or borrow what you need from a colleague in your group or contact the Chemical Management System coordinator to assist you in finding a source of the chemical at LBNL.
• Conduct periodic cleanouts to prevent accumulating unneeded chemicals.
• Procure and use the minimum amount of material required for the operation, or
• Keep working quantities of chemicals to a minimum. Don’t stockpile chemicals. 
• Enter these materials into the Chemical Management System (CMS).

Ventilation

• A fume hood or other appropriate exhaust ventilation system should be used when handling flammable and combustible liquids in a manner that may produce an airborne hazard (such as fumes, gases, vapors, and mists).  This includes procedures such as transfer operations, preparation of mixtures, blending, sonification, spraying, heating, and distilling.

Work Practices

• Control all ignition sources when handling flammable and combustible liquids. 
• Electrically bond and ground containers when transferring Class I flammable liquids and other flammable and combustible liquids at temperatures above their flashpoints.
• Storing and consumption of food is permitted in designated areas only.  See Work Practice Controls for additional information.
• Use a mechanical aid or a pipette bulb for pipetting.
• Open bottles or carboys slowly and carefully and wear protective equipment to guard hands, face, and body from splashes and vapors/gases.
• Wipe drips/residues from containers and work surfaces. 
• Wash hands before leaving the work area and prior to consuming food/beverages.

Personal Protective Equipment (PPE):

Skin and eye contact shall be prevented. The following PPE should be worn when handling these materials.  Additional information may be found in the Personal Protective Equipment Section:

• At a minimum, safety glasses with side shields, laboratory coats (coveralls are acceptable in shop settings) and closed-toe shoes will be worn when handling these materials. This is to be considered as minimum protection and must be upgraded if necessary.
• Additional PPE such as chemical goggles, face shields, chemical aprons, disposable coveralls, chemically resistant gloves and respiratory protection must be worn if there is a greater chance of chemical exposure. An EH&S Industrial Hygienist may be contacted for assistance in selecting appropriate gloves and respiratory protection. The use of respiratory protection requires an industrial hygiene hazard evaluation and a medical clearance followed by a fit test and training by the Industrial Hygiene Group.
• Consult “Eye and Face Protection” in the Personal Protective Equipment Section for guidance on the selection, uses, and limitations of safety glasses, chemical goggles, and face shields.
• Since many chemicals are skin-absorbers (i.e. agents that readily pass through the skin) it is important to select gloves that are chemically resistant to the material.  Consult the PPE section.  This contains a list of skin-absorbing agents and provides detailed guidance for selecting chemically resistant gloves.
• Gloves must be selected on the basis of their chemical resistance to the material(s) being handled, their suitability for the procedures being conducted, and their resistance to wear as well as temperature extremes. Improper selection may result in glove degradation, permeation of the chemical through the glove and ultimately personal exposure to the chemical.  This is a potentially serious situation.  Consult “Gloves” in the Personal Protective Equipment Section for guidance on the selection, uses, limitations, and disposal of chemically resistant gloves.   An EH&S Industrial Hygienist may also be contacted for assistance in selecting appropriate gloves.

Storage

Storage requirements are provided below:  The section entitled Storage Guidelines provides additional information and chemical incompatibilities.  Consult the chemical’s Material Safety Data Sheet for specific storage and incompatibility).

Flammable Storage Lockers and Refrigerators

• Store flammable and combustible liquids in a cool, dry environment free from extremes of temperature and humidity.
• An approved flammable storage cabinet is required for storing flammable liquids totaling 10 or more gallons. These should be constructed of steel and be equipped with self closing doors with a three point latch arrangement.  Storage cabinets connected to an exhaust system provide the best control. Flammable storage cabinets installed as part of new facilities construction and laboratory renovation projects, must be connected to the facility’s supply and exhaust ventilation system  to control vapors and odors and to prevent corrosion to the interior.   The top bung of the flammable storage locker should be connected to a source of non-laboratory supply air.  The lower bung should be connected to the exhaust system.
• Ensure caps and lids are securely tightened on all containers. This prevents evaporation of contents. Teflon liners can be inserted into caps to help form a tighter seal.
• Use drip trays for all liquids.
• No more than 120 gallons of Class I, Class II, and Class IIIA liquids, combined, may be stored in a storage cabinet.  Of this total, no more than 60 gallons may be of Class I and Class II liquids, combined, and not more than three such cabinets may be in a single fire compartment area. (i.e., a room that is separated from other rooms/areas by fire walls).
• Ordinary domestic refrigerators and freezers must not be used for storing flammable liquids because they contain electrical components (light bulbs, switches, contacts and motors) that are potential ignition sources which may initiate a fire or an explosion if flammable vapors are present. Refrigerators and freezers for storing flammable liquids (including ethanol) must be designed, constructed and approved for that purpose Contact Procurement for guidance on purchasing refrigerators and freezers. Domestic refrigerator/freezers as well as units that have been modified to remove spark sources are not acceptable. 

Flammable and Combustible Storage Containers

• Flammable and combustible liquids can be stored in metal or polyethylene safety cans provided they have been approved for such storage, i.e.,  the containers are UL listed or FM approved and that they are equipped
  with a:
• Self-closing cap, automatic vent, and flame arrester
• Current carrying insert embedded into the can for proper grounding, and a
• Funnel.

Table 1. Containers for Combustible and Flammable Fluids

 a Glass containers of no more than 1 gallon capacity may be used for Class IA or IB flammable liquids if such liquid either would be rendered unfit for its intended use by contact with metal or would excessively corrode a metal container so as to create leakage hazard.  NOTE:  This exemption does not apply to the accumulation of noncorrosive ignitable hazardous waste.

b Underwriter Laboratory or Factory Mutual approved available through Procurement.

Gravity-Dispensing Flammable Liquids

Class I B liquids (e.g., ethanol) may be transferred from containers or tanks by gravity through piping, hoses and self- or automatic closing valves that have been reviewed and approved by the Laboratory’s Fire Marshal   Such transfer operations must be done with spill control and secondary containment.  Moreover, the nozzle and containers must be bonded to each other (i.e., electrically interconnected) to prevent static electricity discharges.

Emergency Procedures

• Consult the “Emergency Procedures and Equipment” section for emergency actions regarding chemical spill and personal exposure to chemicals.
• In addition to these requirements, the following applies to flammable and combustible liquid spills:

• Never use combustible or reactive materials (such as paper towels) to clean up or absorb spills of flammable or combustible liquids.  Keep an adequate number of appropriate spill kits to meet anticipated needs. These are commercially available through VWR Scientific.  Typically, products containing diatomaceous earth are used for absorbing organic solvents.
• An emergency eyewash and safety shower should be located in all areas where flammable or combustible liquids are used. In the event of skin or eye contact, flush the affected area for at least 15 minutes and report to Health Services for evaluation and treatment.

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