If there is one thing Americans can agree upon, it is the enjoyment that comes from an outdoor barbeque. Whether a summertime cookout or a fall BBQ to watch a football game, we all love the fun and fellowship that comes from sharing a meal that was prepared outdoors on a grill or smoker. In fact, 64% of Americans own a grill or smoker. The great majority of these are LP fueled gas grills with comparatively few natural gas fired grills. These products can be enjoyed safely when designed, installed, and used in a proper manner. However, given the grill’s use of flammable fuel gas and high temperatures, the potential exists for things to go wrong and result in burn injuries or uncontained fires that spread to the surroundings.
I am quite familiar with safe gas grill design and use as, prior to entering the forensics field, I was the Vice President of Engineering at a gas grill manufacturer. Since then, in my practice as a forensic engineer and fire investigator, I have investigated many structural fires and burn injuries involving gas grills. Typical incidents involve a fire at a grill that spreads to an adjacent residence or an operator that is burned during the use of the grill. Figure 1 shows a grill which was involved in a residential fire. The grill was improperly installed too close to combustible wood supports. Figure 2 shows flames that issued from the operator’s access opening on a gas grill when it experienced a delayed ignition. Excessive LP gas had accumulated in the grill due to a leaking valve. The flames injured the grill’s operator.
Generally, injuries and fires occur when proper procedures are not followed. These procedures relate to the design, installation and use of the grills. Regarding the design of gas grills, there are several relevant product standards. The primary standard is ANSI Z21.58 Standard for Outdoor Cooking Gas Appliances. Larger gas grills are sometimes designed to ANSI Z83.11 Gas Food Service Equipment. Additionally, equipment such as smokers or turkey fryers are covered under ANSI Z21.89 Outdoor Cooking Specialty Gas Appliances. I have designed and had products laboratory approved to each of these standards. The standards include many safety requirements of the product’s design and construction. They also mandate many performance tests that the grill must be able to pass. Also specified are many of the required warnings and information to be supplied in an owner’s manual. Generally, mass produced gas grills have been designed to one of these standards and tested and listed by a testing lab such as UL, ETL or CSA. “Listed” means included on the laboratory’s database of approved products. This is a key step in ensuring a reasonably safe gas grill. Many of the gas grill burn injury cases I have investigated involved unlisted gas grills. These may lack the safe design provisions and proven performance of listed gas grills.
However, even listed gas grills can have problems if they are not installed in a correct manner. Gas grills broadly fall into two categories, those with “self-contained” fuel supplies (like 20 pound LP tanks) or “fixed fuel” grill installations that are supplied with either natural gas service or LP gas from a larger fixed bulk tank. These are illustrated in Figures 3 and 4. Each of these types has specific installation requirements. For the self-contained fuel type with a normal LP cylinder, these installation requirements largely relate to following the manufacturer’s requirements as to the proper location and operation of the grill. Additionally, there are code regulations regarding the use of such grills. For example, gas grills with 20 pound LP cylinders cannot be used inside buildings and are generally not allowed to be used on balconies of apartment buildings.
Grills that are permanently installed in a surround or island (see figure 4) and are supplied with fuel gas from a fixed fuel source have more involved code requirements. Codes require that these grills be listed to either ANSI Z21.58 or ANSI Z83.11. Additionally, the installation must be in accordance with the manufacturer’s instructions. In some locales, the construction of the grill island and installation of the grill will require an installation permit and inspection. In addition to the installation of the grill, the fuel supply system itself, whether LP or natural gas, often will require an installation permit with inspection. The fixed fuel supply system itself must be designed and installed per the requirements of the relevant gas code, typically either NFPA 54 National Fuel Gas Code, NFPA 58 Liquified Petroleum Gas Code and/or the International Fuel Gas Code.
Once the gas grill has been manufactured and installed in a proper manner, the user must operate the grill in an appropriate manner. This generally requires operating and maintaining the grill in accordance with the manufacturer’s instructions. A common operational problem is the delayed ignition of accumulated fuel that creates a larger than normal fire which burns the operator. Another problem that occurs is a fire at the grill that spreads to the surrounding structure. Problems in the design, installation or operation of the grill may cause or contribute to these situations.
If you have a burn injury or fire incident that involves a gas grill, contact Warren for an informed investigation that will consider all the potential causes of the incident.
John Holecek, senior consulting engineer at Warren, is a licensed professional engineer in South Carolina, North Carolina, Alabama, Florida, Georgia, Ohio and Virginia and has both a Bachelor of Science in Mechanical Engineering and Master of Science in Mechanical Engineering from the University of South Carolina. A certified fire and explosion investigator by the National Association of Fire Investigators, John has more than 22 years experience in the design of industrial process equipment and is extremely knowledgeable in ICC, NFPA and OSHA codes and standards. He pairs more than 13 years of experience supervising manufacturing operations with deep knowledge in areas such as applied industrial heat transfer in oven design, industrial electrical process and motor control systems, material handling systems and fire protection systems. In addition he’s designed paint finishing systems, and commercial and consumer gas fired cooking appliances. John, who has more than 22 years’ experience managing outside contractors in site safety requirements and installation of industrial process equipment, is well versed in federal and state worker safety and environmental regulations.