New Advisory Highlights Risks to Older Plastic Gas Pipes in High-Heat

New Advisory Highlights Risks to Older Plastic Gas Pipes in High-Heat Environments

The Pipeline and Hazardous Materials Safety Administration (PHMSA) has issued an advisory bulletin (ADB–2026–01) reminding natural gas distribution operators to take a closer look at older plastic piping - especially when it may be exposed to elevated temperatures.

The advisory follows a tragic 2023 explosion in West Reading, Pennsylvania, that resulted in seven fatalities and multiple injuries. National Transportation Safety Board (NTSB) investigators found that a retired plastic service tee installed in 1982 had degraded over time and leaked natural gas. Heat from a nearby underground steam pipe accelerated the deterioration of the plastic component. The gas migrated into a building, accumulated, and ultimately ignited.

NTSB also highlighted a broader industry concern: operators may not actually know where their plastic assets sit in heat-risk environments, meaning mitigation efforts may never get triggered. Even if field crews encounter hot spots, some operators may lack procedures and training to ensure that information makes it into the integrity management loop.

Why This Matters

Plastic pipe has been widely used in natural gas distribution systems for decades. While generally safe and effective, certain older materials - particularly some installed between the 1960s and early 1980s - are known to be more vulnerable to cracking and degradation. The risk can increase significantly when pipes are exposed to elevated ground temperatures, such as those caused by nearby steam lines, electric infrastructure, or other heat sources.

Small increases in temperature can dramatically accelerate crack growth and material breakdown in susceptible plastics. In some cases, operators may not be fully aware of nearby heat sources or how environmental conditions could affect underground assets.

Key Takeaways for Operators

PHMSA is urging operators to strengthen their Distribution Integrity Management Programs (DIMP) by:

• Reviewing the NTSB’s West Reading investigation report and past PHMSA advisory bulletins
• Identifying plastic pipe and components that may be susceptible to cracking or heat-related degradation.
• Conducting a one-time inventory of plastic assets in areas that have or may experience elevated temperatures.
• Evaluating and ranking risks—recognizing that even low-likelihood events can present high risk if consequences are severe.
• Implementing mitigation measures, such as enhanced leak detection, replacement programs, and improved data collection.
• Ensuring proper clearance or insulation from heat sources when installing new plastic mains.

The advisory also reinforces the importance of understanding system materials, environmental conditions, and potential threats—even if no prior leaks have occurred.

A Proactive Approach to Safety

PHMSA emphasizes that operators must use reasonably available information to understand their systems and address both known and potential threats. This includes maintaining strong records, training field personnel to identify environmental risks, and incorporating lessons learned from past incidents. Information discovered during routine maintenance, construction activities, and review of past incidents (and near misses) needs to be fed into the integrity management loop so that these risks can be properly addressed.

Safety in natural gas distribution depends not only on the materials in the ground, but also on awareness of the environment around them. Effective integrity management programs depend on the identification and mitigation of threats that are present in your system.

While the bulletin does not create new regulatory requirements, it serves as a clear reminder: proactive risk management - especially around aging plastic assets and elevated temperatures - is essential to preventing future incidents. 

If you or your team need help navigating this piece of regulation, we have experts on staff ready to help you align to this potential change. Contact us today.