Stop Guessing and Get Smarter about Combustible Gas Leak Detection

Industrial combustible gas leaks, such as methane, propane, or other hydrocarbons, can occur in gas piping systems, valves and regulators, flanges and fittings, and in a variety of other gas connections. The potential for such leaks is why it is standard practice to routinely check such systems for leaks. Worker safety, regulatory compliance, protecting infrastructure and the environment, and preventing costly downtime all mean leak detection is a non-negotiable.

OSHA Regulations on Leak Detection of Combustible Gases

Does OSHA require that you routinely check for combustible gas leaks? Except for confined space requirements, there are no specific OSHA regulations on leak detection for combustible gases.

However, this does not mean routine leak detection for combustible gases, or any other hazardous gas, doesn’t fall under OSHA requirements. Safety auditors can simply cite OSHA’s General Duty Clause Section 5(a)(1). It says that each employer “shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees;”.

This means that if the potential for leaks is present and either continual monitoring, routine leak detection, or both, are not performed, employees may be put at risk. If so, this is a violation of OSHA requirements.

It is also important to mention that other regulating agencies may have jurisdiction in some contexts. Agencies such as the NFPA, DOT, and the EPA, may have their own requirements for routine leak detection of combustible gases.

What is a Leak Check

Because combustible gas leak checks can be an OSHA compliance issue, it is important that one understands exactly what a leak check is and is not. To do this, an important distinction needs to be made between two common methods of measuring combustible gases. The two common methods are testing for %LEL (Percent of Lower Explosive Limit) or testing for PPM (Parts Per Million).

Think of testing for %LEL as a safety alert tool. Gas monitors that test for %LEL alert the user when explosive levels of combustible gases are accumulating in the air. Per OSHA requirements, the monitors will alarm at 10% LEL, 25%, 50%, and even 100%. This is not leak detection, although it can certainly indicate the presence of a leak. In fact, when these alarms are triggered, one should leave the space or room immediately.

The second method is much more sensitive at detecting low levels of combustible gases. This method tests for combustible gases in the PPM range (Parts Per Million). This is a method used for leak detection. You can think of it as measuring trace amounts. For example, PPM amounts can be detected at levels as low as 0-500 PPM. By comparison, 10% LEL Methane is equivalent to 5,000 PPM. This PPM testing method therefore provides an accurate way to “sniff out” and locate the source of a combustible gas leak at very low levels.

A leak check at low levels, then, is performed using a portable combustible gas monitor that tests in the PPM range. Such meters will usually have a wand or probe to help pinpoint the source of the leak. The wand or probe is placed at potential leak locations. As the PPM levels rise, the presence of a leak has likely been located.

Be aware that in some cases, such as for monitoring wells at landfills or certain contexts for gas utility companies, the aforementioned PPM method for low level leak detection will not be sufficient. In these contexts, levels of methane might far exceed the LEL and even the UEL (upper explosive limit). At such high levels, there are other methods for combustible gas detection such as testing for Percent by Volume using thermal conductivity sensor technology.

Making Sense of the Options

If you have searched for combustible/methane gas leak check monitors, you may have noticed that there are a lot of options at wildly different price points. Prices range from the low hundreds to nearly a thousand dollars. Why such large differences in price?

In the case of low level combustible gas leak check monitors, the difference is found mainly in the sensor technology used and the capabilities of the monitor itself. 

In what follows below, I’ll briefly talk about the capabilities of the monitors and not the sensor technology.

Generally speaking the differences in price relate to the following capabilities:

1. Calibration. The inexpensive monitors can be zeroed but usually can’t be calibrated to the industry standard of 50% LEL (2.5% volume) of methane. Depending on your use case, this could be a problem.
2. LEL and PPM Detection. The inexpensive monitors generally can’t check for both LEL and PPM levels of combustible gases. In other words, they have the leak check capability for levels in the PPM range (usually topping out at 10,000 PPM), but they lack the “safety alert” feature of testing for a dangerous explosive atmosphere in the %LEL range. Again, depending on your context, this limitation may or may not be a problem.
3. Because of (1) and (2) above, the fine print for most of the inexpensive leak detectors states that it is not a PPE device.
4. The sensor in the inexpensive leak detectors usually cannot be changed out. However, they do generally last quite a long time.

Conclusion

So which one is right for you? The answer to that question is usually found in your company safety policies, your insurance company requirements, or the specific applications you face on a day to day basis.

We, Major Safety, sell the GX-Force. It may or may not be the right choice for you. We would be glad to speak with you about your specific context and give guidance.