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ANSI Z21.97-2017 / CSA 2.41-2017: Technical Guide to Outdoor Cooking Gas Appliance Safety and Compliance
A comprehensive breakdown of the scope, critical requirements, and implementation strategy for manufacturers and engineers.
Scope and Application
ANSI Z21.97-2017 • CSA 2.41-2017, formally titled “Outdoor Cooking Gas Appliances”, establishes the comprehensive safety, construction, and performance requirements for factory-built gas-fired cooking appliances intended for outdoor use. This standard is the primary benchmark for North American manufacturers of a wide range of products, including residential gas grills, side burners, portable stoves, and integrated outdoor cooking centers.
The standard applies to appliances designed for use with natural gas, manufactured (LP) gas, or liquefied petroleum gas (propane) in either fixed, stationary, or portable configurations. It covers all integral components including the gas train, burners, control valves, ignition systems, cylinder mounting devices, and structural enclosures. Notably, the 2017 edition harmonized text between the ANSI and CSA versions more rigorously, clarified requirements for electronic components (such as rotisserie motors and infrared igniters), and strengthened weathering performance criteria.
Key Distinction: This standard is specific to outdoor cooking appliances. It does not cover permanent residential kitchen ranges (ANSI Z21.1 / CSA 1.1), patio heaters (ANSI Z21.88 / CSA 2.36), or deep-fat fryers (ANSI Z21.90 / CSA 2.46). Certified appliances bearing the Z21.97 mark are explicitly labeled “For Outdoor Use Only.”
Key Technical Requirements and Design Criteria
The 2017 edition of the standard mandates rigorous testing across several critical safety domains. Engineers designing for compliance must address material selection, gas system integrity, combustion performance, and environmental resistance. The table below summarizes the critical performance criteria derived from the standard.
| Performance Aspect | Primary Clause | Design Requirement | Test Parameter Summary |
|---|---|---|---|
| Gas Cylinder Connection | Sec. 2.4 | Must incorporate a Type 1 / QCC1 connector with thermal shut-off. | Connect/disconnect cycle test; leak test at 20 psi; thermal shut-off must activate at 250°F ± 50°F. |
| Burner Performance | Sec. 2.12 | No flame lifting, flashback, floating, or excessive yellow tipping. | Operate at maximum and minimum input; measure flame stability under draft conditions. |
| Rain / Weather Resistance | Sec. 2.18 | Appliance must maintain safe operation or fail safe (gas shut off) during exposure. | Simulated rainfall at 0.125 in/min for 30 minutes; burner must remain lit or safety valve closes. |
| Structural Stability | Sec. 2.6 | Appliance must not tip over under normal or abnormal loading conditions. | 100 lb (45.4 kg) load applied to the cooking surface; test in worst-case orientation. |
| Marking & Instructions | Sec. 3 | Permanent marking for gas type, pressure, “For Outdoor Use Only”, and clearance. | Visual examination; permanency test (rub test and water immersion). |
2.1 Gas Train Integrity
The standard places significant emphasis on the gas train components. All gas-carrying parts must be constructed from corrosion-resistant materials or adequately protected against environmental degradation. For LP-gas appliances, the cylinder connection must include a Type 1 (QCC1) device that prevents gas flow until a positive seal is made. The 2017 update reinforced the requirement for a thermal element that shuts off the gas supply if the cylinder valve or regulator exceeds a safe temperature, preventing catastrophic cylinder failure in a fire event. All gas connections downstream of the regulator must withstand a non-volatile pressure test without leakage.
2.2 Burner and Heat Distribution
Burner designs must demonstrate stable ignition, consistent flame characteristics, and reliable re-ignition if a flame is extinguished. The standard requires that burner port loading (Btu/h per inch of port length) does not exceed limits that cause flame disturbance of flashback. Furthermore, the appliance must be equipped with a valve that can be turned off quickly. For multi-burner appliances, the 2017 edition tightened the requirements for cross-lighting to ensure all burners ignite smoothly without dangerous accumulation of unburned gas.
Common Non-Compliance Issue: Failing the rain test due to inadequate drainage or unsealed electrical enclosures is a frequent cause of certification delays. The 2017 edition specifically increased the scrutiny on water ingress points around control knobs and electronic ignition modules.
Implementation Highlights and Testing Protocol
Successfully navigating certification to ANSI Z21.97-2017 requires a robust design validation strategy. Engineers must prioritize several complex test procedures during the prototype phase.
3.1 Rain and Weather Resistance Testing
One of the most challenging evaluations is the water resistance test outlined in Clause 2.18. The appliance is operated at maximum input while subjected to a standardized spray pattern simulating heavy rain. If the burner flame is extinguished, the gas supply must be automatically shut off by the safety valve system. Designs that rely solely on a snap-acting thermocouple must ensure the response time is within the allowable limit. This test particularly impacts the placement of air shutters, burner venturis, and control panel seals.
3.2 Stability and Structural Integrity
The stability test (Clause 2.6) evaluates the appliance’s resistance to tipping with a loaded cooking surface. The test simulates a user leaning on the handle or placing a heavy weight (e.g., a turkey fryer pot or full rotisserie load) on the side or front. Designers must ensure the center of gravity and wheel locations (if equipped) provide a sufficient safety margin. Locking casters or wider leg spreads are common solutions for meeting this requirement. The standard also requires an evaluation of the strength of handles, doors, and shelves.
Critical Failure Risk: A grease fire scenario that causes flame to impinge on the gas hose, regulator, or cylinder is considered an immediate and mandatory failure under the abnormal operation tests. Grease management systems and flame tamers must be rigorously validated.
Compliance Notes and Regulatory Adoption
Compliance with ANSI Z21.97-2017 is a de facto requirement for market access across North America. While the standard is technically voluntary at the federal level, it is widely adopted by state and local building codes (e.g., the International Fuel Gas Code and Uniform Plumbing Code reference this standard). Furthermore, retailers and insurance carriers typically require proof of third-party certification.
4.1 Third-Party Certification
Manufacturers must engage an accredited Nationally Recognized Testing Laboratory (NRTL) or a Standards Council of Canada (SCC) accredited certification body. Organizations such as CSA Group, UL (Underwriters Laboratories), and Intertek are typical certifiers. The certification process involves an initial design review, witness testing, and a robust follow-up factory inspection program to ensure ongoing production complies with the certified design. The 2017 standard update provided clearer pathways for certifying appliances with integrated electrical controls, ensuring they meet both the gas safety requirements and the relevant electrical safety standards (e.g., UL 969 for markings, CSA C22.2 for electrical components).
Market Advantage: Achieving certification to the combined ANSI/CSA standard streamlines market entry for both the United States and Canada. A single test report and certification mark (e.g., CSA Blue Star or UL Mark) can satisfy both nations’ jurisdictional requirements when the standard is harmonized.
Frequently Asked Questions (FAQs)
Q: What major changes were introduced in the 2017 edition of Z21.97 compared to the 2010 edition?
A: The 2017 edition incorporated significant updates to the rain and water ingress testing protocols, requiring a more rigorous simulation of exposure. It also provided clearer requirements for the durability of electronic components (such as rotisserie motors and integrated lights), added criteria for infrared burner performance, and enhanced the marking requirements for clearances to combustibles. The standard also harmonized the requirements between the ANSI and CSA versions more thoroughly.
A: The 2017 edition incorporated significant updates to the rain and water ingress testing protocols, requiring a more rigorous simulation of exposure. It also provided clearer requirements for the durability of electronic components (such as rotisserie motors and integrated lights), added criteria for infrared burner performance, and enhanced the marking requirements for clearances to combustibles. The standard also harmonized the requirements between the ANSI and CSA versions more thoroughly.
Q: Does ANSI Z21.97-2017 apply to portable camping stoves or tabletop grills?
A: Yes, the standard applies to all factory-built outdoor cooking gas appliances, including portable camping stoves and tabletop units, provided they are intended for cooking and use with natural gas, LP-gas, or propane. However, appliances that are strictly for non-cooking purposes (heating) or those that exceed specific size/input thresholds for portable appliances may be covered by other related standards in the Z21 series. Refer to the specific scope definition in Section 1.1 for exact exclusions.
A: Yes, the standard applies to all factory-built outdoor cooking gas appliances, including portable camping stoves and tabletop units, provided they are intended for cooking and use with natural gas, LP-gas, or propane. However, appliances that are strictly for non-cooking purposes (heating) or those that exceed specific size/input thresholds for portable appliances may be covered by other related standards in the Z21 series. Refer to the specific scope definition in Section 1.1 for exact exclusions.
Q: What is the significance of the “Rain Test” in this standard?
A: Clause 2.18 requires the appliance to continue operating safely or shut off safely if exposed to a significant rain event. The test involves operating the appliance at maximum input while simulating rainfall at a specific rate (0.125 in/min) for 30 minutes. The critical safety metric is that the burner must not go out, or if it does, the gas supply must be completely and automatically interrupted by the flame failure safety device. This prevents the dangerous accumulation of unburned gas.
A: Clause 2.18 requires the appliance to continue operating safely or shut off safely if exposed to a significant rain event. The test involves operating the appliance at maximum input while simulating rainfall at a specific rate (0.125 in/min) for 30 minutes. The critical safety metric is that the burner must not go out, or if it does, the gas supply must be completely and automatically interrupted by the flame failure safety device. This prevents the dangerous accumulation of unburned gas.
Q: How does the standard ensure the safety of LP-gas cylinders connected to the appliance?
A: The standard mandates the exclusive use of a Type 1 (QCC1) connection. This device prevents gas flow unless the connection is fully and correctly engaged (positive shut-off). Additionally, the connector and regulator assembly must incorporate a thermal shut-off device. If the temperature around the cylinder valve rises to dangerous levels (approximately 250°F to 300°F) during a fire, the thermal element activates, sealing the cylinder and preventing pressurized gas from feeding the flames.
A: The standard mandates the exclusive use of a Type 1 (QCC1) connection. This device prevents gas flow unless the connection is fully and correctly engaged (positive shut-off). Additionally, the connector and regulator assembly must incorporate a thermal shut-off device. If the temperature around the cylinder valve rises to dangerous levels (approximately 250°F to 300°F) during a fire, the thermal element activates, sealing the cylinder and preventing pressurized gas from feeding the flames.