Fire Safety, Inc. - Total Fire Protection

Commercial Cooking Facilities

An Introduction... The first restaurant systems were installed more than 35 years ago. At that time restaurant owners and fire fighters recognized that a fire in a cooking appliance could spread rapidly to the hood or duct and quickly spread to involve an entire kitchen. Frightening, because statistics show that many restaurants never reopen after a major fire.

First Systems Introduced... Ansul developed the first dry chemical fire suppression system designed exclusively for restaurant hood and duct protection. Restaurant owners, insurance companies and fire departments were quick to recognize the systems as an effective solution.

Other manufacturers joined in developing newer and better systems to protect this unique application. Fire Safety sold our first system in the late 1960's as this market continued to expand and evolve.

An Evolving Application... In about 1982 wet chemical systems were introduced. These new systems provided solutions to new cooking appliances and provided an extinguishing agent that was easier to clean after a discharge.

UL300 Changes... As time continued to move on, the methods in preparing food changed. Hotter cooking appliances, round the clock operations, and high efficiency appliances all combined to demand a change in the fire protection application for these hazards. The two changes in commercial food preparation techniques that have had the most impact on the protection in recent years are the use of vegetable cooking oils for frying and the use of "energy efficient" appliances.

• Over the years, the use of animal fats for frying foods has given way to the use of vegetable oils that help lower fat and cholesterol content of food. Vegetable oils burn at a higher temperature than animal fats and create fires that are more difficult to extinguish.

• Energy efficient cooking appliances are now used extensively in restaurants. Highly insulated fryers help reduce fuel consumption and improve cooking times by maintaining a more consistent temperature. They also help keep cooking oils and metal appliances hotter longer and make fire extinguishment more difficult.

In the past, fire suppression systems were not tested with these specific hazards in mind, so new test protocols had to be developed. On November 21, 1994, Underwriters Laboratories adopted a new standard, UL 300 - Fire Testing of Fire Extinguishing Systems for Protection of Restaurant Cooking Areas. All manufacturers wanting to sell UL listed fire suppression systems after that date had to resubmit their systems to UL for testing.

The UL 300 standard now considers cooking appliance design; cooking agent ignition characteristics and "worst case" fire suppression scenarios. The new testing procedures are more difficult to pass than previous procedures, but more realistically simulate existing fire hazards in restaurants.

Significant changes in the design of fire suppression systems were required to pass the UL tests. UL 300 test protocols produce a more intense fire that is more difficult to extinguish and far more difficult to secure against reflash than previous test protocols. During preliminary testing, it became apparent that cooling is a critical factor in successful extinguishment and containment of "modern" restaurant cooking fires. To achieve the required cooling effect, the design of the fire suppression systems was altered to increase the amount of wet chemical extinguishing agent* used. For example, manufacturers, on average, had to use five times wet chemical extinguishing agent to extinguish UL 300 test fires involving fryers.

Appliances affected by the UL 300 protocol changes include fryers, griddles, ranges, charbroilers (gas radiant, electric, lava rock), and woks. The UL 300 standard did not change plenum, hood and duct test protocols and did not affect chain broilers, upright broilers, charcoal and mesquite cooking methods.

Wet Chemical fire suppression systems, with their increased supply of extinguishing agent, were effective in extinguishing UL 300 test fires. Dry chemical suppression systems and water spray devices were not.

Dry chemical extinguishing agents were used extensively in older fire suppression systems, but not as often in recent years. However, many dry chemical systems are still in use today and these systems may not be effective extinguishing modern restaurant cooking fires. Testing by fire equipment manufacturers showed that while dry chemical systems could knock down the UL 300 test fires, the fires would reflash and continue to burn due to a lack of cooling. No listings, to date, have been obtained for dry chemical systems tested to the UL 300 standard.

Water spray devices, used with water sprinkler systems, also raise concerns in the extinguishment of today's restaurant cooking fires. Water spray devices are not presently tested according to the new UL 300 standard. However, testing by the Fire Equipment Manufacturers Association showed that water spray devices took seven to ten minutes to extinguish test fires, versus three seconds for wet chemical fire suppression systems.

*Normally a solution of water and potassium carbonate-based chemical, potassium acetate-based chemical, or a combination thereof that forms an extinguishing agent.