Gas Leak Emergency Response

Homeowner Summary

A gas leak is one of the most dangerous emergencies that can occur in your home. Natural gas and propane are inherently odorless — utility companies add mercaptan (a chemical that smells like rotten eggs or sulfur) so you can detect leaks by smell. If you smell rotten eggs in your home, treat it as an immediate life-safety emergency. Natural gas is lighter than air and rises, dispersing throughout a home. Propane is heavier than air and sinks to the lowest point — basements, crawlspaces, and ground-level rooms — making propane leaks particularly dangerous because the gas pools in concentrated, explosive pockets.

Both natural gas and propane are explosive when mixed with air at concentrations between 5% and 15% (natural gas) or 2.1% and 9.5% (propane). A single spark from a light switch, phone, doorbell, or appliance motor can trigger an explosion. This is why the first rule of a gas leak is: do NOT activate or deactivate ANY electrical device. Do not flip light switches on or off, do not use your phone inside the house, do not start a car in the garage, and do not use any appliance. Simply get everyone out of the house and call for help from a safe distance.

Gas leaks can originate from aging gas lines, loose fittings, damaged appliance connectors, cracked heat exchangers in furnaces, or seismic/ground movement. Even small leaks are dangerous — they can accumulate over time in enclosed spaces.

IMMEDIATE EMERGENCY ACTIONS

If you smell gas or suspect a gas leak, follow these steps in exact order:

1. DO NOT flip any switches. Do not turn lights on or off. Do not press any buttons. Do not use your phone inside the house. Any electrical spark can ignite gas.

2. DO NOT light matches, candles, or lighters. No open flames of any kind.

3. DO NOT start any vehicles in the garage or near the home.

4. DO NOT try to find the leak. Leave that to professionals with gas detection equipment.

5. Open doors and windows as you leave — only if they are easily accessible on your exit path. Do not go out of your way to open windows. Ventilation helps, but evacuation is the priority.

6. Evacuate all occupants immediately. Account for all family members, guests, and pets. Assist anyone with mobility limitations.

7. Move to a safe distance. Get at least 300 feet (approximately one football field) away from the home, upwind if possible.

8. Call 911 from outside using a cell phone or a neighbor's phone. Then call your gas utility's emergency number (found on your gas bill — program it into your phone now, before an emergency).

9. Do NOT re-enter the home until the fire department or gas utility has declared it safe.

What NOT to Do

• NEVER flip electrical switches on or off (even turning off a light can create a spark)
• NEVER use a phone, tablet, or any electronic device inside a gas-filled space
• NEVER use a garage door opener (electric motor creates sparks)
• NEVER ring a doorbell (electrical contacts create sparks)
• NEVER start a car or any engine near the suspected leak
• NEVER attempt to repair a gas leak yourself
• NEVER re-enter the home until cleared by fire department or utility company
• NEVER ignore a faint gas smell — even a small leak can become catastrophic

Gas Meter Shutoff Procedure

Only shut off gas at the meter if you can do so safely while evacuating — do NOT go back into a gas-filled area to reach the meter.

1. Locate your gas meter (typically on the exterior of the home, near the street)
2. Find the shutoff valve on the supply side (pipe coming from the street to the meter)
3. The valve has a rectangular tab (or lever) that needs a 1/4 turn (90 degrees) to close
4. Use an adjustable wrench or dedicated gas shutoff wrench (12" crescent wrench works)
5. Turn the tab so it is perpendicular (crosswise) to the pipe — this is the OFF position
6. When the tab is parallel (in line) with the pipe, gas is flowing (ON)

Important: Once you shut off gas at the meter, do NOT turn it back on yourself. Only a licensed gas utility technician or plumber should restore gas service. Each gas appliance must be individually relit and checked for leaks.

Recommended: Keep a dedicated gas shutoff wrench strapped to the gas meter or in a clearly labeled, easily accessible location near the meter.

Natural Gas vs Propane: Key Differences

| Factor | Natural Gas | Propane (LP) | |--------|------------|--------------| | Weight relative to air | Lighter (rises) | Heavier (sinks) | | Explosion risk | Disperses upward | Pools at ground level — MORE DANGEROUS in enclosed spaces | | Explosive range | 5-15% concentration in air | 2.1-9.5% concentration in air (ignites at lower concentration) | | Supply | Continuous utility line | Finite tank — can run out (pilot lights extinguish, then gas re-enters without ignition) | | Shutoff location | Meter on exterior wall | Tank shutoff valve (handwheel on top of tank) | | Smell strength | Moderate mercaptan | Strong mercaptan (typically more noticeable) | | Basement risk | Lower (gas rises to upper floors) | CRITICAL (gas sinks to lowest level and pools) |

Propane-specific danger: Because propane is heavier than air, it settles into basements, crawlspaces, and any low-lying area. A propane leak in a home with a basement can create a lethal explosive concentration at floor level while the air at head height smells relatively normal. If you have propane and smell even a faint odor, evacuate immediately.

Warning Signs

• Rotten egg / sulfur smell (the most reliable indicator — mercaptan is added specifically for detection)
• Hissing or blowing sound near gas lines, appliances, or meter
• Dead or dying vegetation in a line pattern across the yard (underground gas line leak)
• Bubbling in standing water near outdoor gas lines
• White mist or fog near gas lines (pressurized gas escaping)
• Pilot lights that frequently go out (may indicate supply interruption or draft from leak)
• Higher-than-normal gas bills without increased usage
• Physical symptoms: Headache, dizziness, nausea, fatigue, or breathing difficulty in the home that improves when you leave (possible gas or CO exposure)

Pro Detail

Common Leak Sources

• Flexible appliance connectors: Corrugated stainless steel tubing (CSST) is vulnerable to lightning damage if not properly bonded. Older uncoated brass connectors corrode over time
• Threaded pipe joints: Pipe dope or Teflon tape deteriorates over decades; joints in walls and ceilings are inaccessible and impossible to inspect
• Appliance connections: Gas ranges, dryers, water heaters, and furnaces — connections can loosen from vibration or movement
• Gas valve packing: Valves on older systems leak around the stem when operated after years of non-use
• Earthquake/settlement: Ground movement can stress buried lines and indoor piping
• Corrosion: Underground black iron pipe corrodes externally; copper and brass fittings corrode internally in some soil/water conditions

Detection and Testing

• Soap bubble test: Apply soapy water solution to joints and connections — bubbles indicate a leak. Professional method for small leaks
• Combustible gas detector: Electronic handheld sensors detect gas concentration in PPM. Every gas technician carries one
• Pressure drop test: Pressurize the gas system to a set PSI, close all valves, and monitor for pressure drop over time (indicates a leak somewhere in the system)
• Flame ionization detector: Laboratory-grade detection for very small leaks

Code & Compliance

• NFPA 54 / IFGC: National Fuel Gas Code governs gas piping installation in most jurisdictions
• CSST bonding: Corrugated stainless steel tubing must be bonded to the home's grounding system per current code (reduces lightning damage risk)
• Leak testing: All new gas installations must be pressure-tested before activation
• Gas detector requirements: Some jurisdictions now require combustible gas detectors in homes with gas appliances (in addition to CO detectors)
• Appliance connectors: Maximum 6 feet for most residential connections; must be accessible (not through walls, floors, or ceilings)

Shipshape Integration

Shipshape provides critical gas safety monitoring and response:

• Combustible Gas Sensors: Integration with smart gas detectors triggers immediate emergency alerts when gas is detected. Alert includes leak severity level and recommended actions
• Emergency Notification Chain: Gas leak detection triggers multi-channel alerts: push notification to homeowner, SMS to all household members, alert to assigned dealer/plumber, and (if configured) automatic 911 notification
• Appliance Tracking: Records age and type of all gas appliances, flexible connectors, and gas line materials. Flags aging components (15+ year connectors, uncoated CSST) as safety concerns in the Home Health Score
• Evacuation Guidance: Emergency alert includes step-by-step evacuation instructions displayed prominently on mobile app, customized to the home layout
• Post-Emergency Documentation: After the emergency is resolved, Shipshape creates an incident record including timeline, response actions, and any recommended repairs — useful for insurance claims and future reference
• Dealer Emergency Routing: Gas leak alerts route to the nearest available gas-qualified dealer or plumber with the home's gas system details for rapid response
• Preventive Alerts: Annual reminders for gas line inspection, connector replacement, and gas detector battery/sensor replacement