Natural gas safety

It helps to know where gas is used in your home before thinking about safety. The usual gas appliances are boilers, furnaces, stoves and water heaters, and some homes also have gas lamps, grills or pool heaters outside the building. Natural gas itself is not toxic, but large amounts of it in an enclosed space can cause suffocation. The bigger everyday risk comes from burning it.

When natural gas is burned incorrectly, it can produce carbon monoxide. Gas appliances that are not working right or are not vented properly can lead to a dangerous buildup of CO. That is why gas safety and carbon monoxide safety go together, and why the vent pipes matter as much as the appliance.

Source: Peoples Gas

Gas in your pipes has a smell on purpose. Gas utilities add a harmless odorant called mercaptan to natural gas, which gives it a distinct smell, similar to rotten eggs, that is easy to notice if there is a leak. Without that added smell, a leak would be much harder to notice.

The smell is a good warning, but not a perfect one. Odorant fade is uncommon, but it happens when a physical or chemical process lowers the level of odorant, and it can happen in both existing gas pipelines and new installations. If you ever smell gas, follow the safety steps at the end of this page.

Source: Peoples Gas · Nicor Gas

Some homeowners add a natural gas detector as an extra warning. A methane (natural gas) detector pulls in the air around it, and if it detects a dangerous level of natural gas in your home, its light flashes, it makes a loud noise, or both. Your detector's user manual gives its testing intervals and explains its light and sound patterns, so you can check that the detector and its alarm are working.

A carbon monoxide alarm watches for a different gas. Carbon monoxide has no smell or color and cannot be noticed by your senses, so people may not know they are breathing it. Some devices cover both: one federal building science guide suggests a plug-in combination explosive gas (natural gas and propane) and carbon monoxide alarm near a gas water heater, for early warning of a gas leak or carbon monoxide. Our carbon monoxide page explains where CO alarms go and what the law requires.

Source: Nicor Gas · U.S. Consumer Product Safety Commission · U.S. Department of Energy

Gas reaches your appliances through a meter and then your own pipes. The gas utility's guide for Chicago customers says customers are responsible for the pipes that leave the meter and serve the gas appliances throughout their property. Buried piping can corrode or wear over time, which could lead to leaks, so all customer-owned buried gas piping should be inspected from time to time by a qualified contractor. If underground gas lines run from your meter to outdoor appliances such as a pool heater, gas grill or gas lamp, have a qualified contractor locate and mark them.

A few simple habits protect the pipes you cannot see. If your gas meter is outdoors, keep it clear of debris so it can be reached during service calls and emergencies and so the flow of gas is not blocked. Before digging, planting or landscaping, you must call 811 or contact your local one-call system at least two business days before you dig. Gas connections that are not working properly are a fire hazard and can contribute to health problems. Installing, maintaining or repairing a gas appliance is a job for a qualified contractor or licensed professional.

Source: Peoples Gas · ENERGY STAR · Nicor Gas

Gas appliances need a yearly look even when they seem fine. Federal health guidance says to have your heating system, water heater and any other gas, oil or coal burning appliances serviced by a qualified technician every year. The EPA recommends that a fuel-burning furnace, stove or fireplace be inspected and serviced before each heating season to protect against carbon monoxide poisoning. A dirty burner or a cracked heat exchanger (the metal wall between the flame and your air) causes the burner to work improperly, and either can make the equipment less safe and less efficient.

A combustion safety check follows a set of steps. Federal guidance for this work says to inspect the visible parts of a furnace's combustion chamber for cracks, holes and corrosion, and to test the heat exchanger for leaks. A technician watches the flame before and after the blower comes on, because a disturbed flame may point to a heat exchanger leak. They measure carbon monoxide in the vent after the main burner has run for 5 minutes. They check that the gas pressure is in an acceptable range by measuring it or timing the gas meter.

The vent pipes deserve the same attention. A contractor should check flues and flue connectors for tight, secure fittings and for rust or cracks that could let toxic gases into the home. The CPSC notes that heating contractors do not normally check chimneys and flues, so ask them to include the venting system in their inspection. If you would like a check-up, tell us which gas appliances you have.

Source: CDC · U.S. EPA · ENERGY STAR · U.S. Department of Energy · U.S. Consumer Product Safety Commission