Thermal liquids are commonplace in many industrial environments to power and process the equipment and systems necessary to get work done or put work in place. However, with temperatures of such fluids ranging from 130 to more than 1,100 degrees Fahrenheit, there's inherent risk involved with the handling of such liquids. And if they're not handled with proper care, the outcome could be disastrous.

In this post, we'll discuss what thermal liquids are, how they're used, the key advantages and disadvantages of using them, thermal liquid protective clothing, and more.

What is a Thermal Liquid?

A thermal liquid, often referred to as a thermal fluid or heat transfer fluid (HTF), works by transferring heat from one component to another. Such fluids are often used in environments where heating or cooling is required to maintain a certain temperature for systems or equipment to function properly. But, these fluids can get extremely hot - and if proper precautions aren't taken, the consequences can be dire.

Some of the most common thermal liquids include water, water-glycol, and thermal oils. Each has its fair share of pros and cons. Heat transfer fluids are still commonly used to maintain temperatures at low pressures because they tend to be safer than alternative measures - like steam - and can offer several years of effective use.

What Industries Use Thermal Liquids?

A variety of industries rely on thermal liquids. Some of these industries include:

  • Food and beverage; meat processing and production
  • Chemical processing; reactors and continuous processing
  • Asphalt and concrete; heating and mixing
  • Converting; printing, laminating, rolling, pressing
  • Petrochemical; catalysis, distillation, synthesis
  • Oil and gas; refining and production
  • Building materials; engineered woods and roofing compounds
  • General manufacturing

Pros and Cons of Using Thermal Liquids

There are various pros and cons of using thermal liquids in industrial environments.


Some of the advantages of using thermal liquids include the longevity of their use and how they're a safer alternative to steam when it comes to performing at high temperatures and at low pressures. They also tend to be reliable and fairly maintenance-free over time.


Disadvantages of using thermal liquids—While thermal liquids present a safer alternative than steam, they still present a serious safety hazard if they're not handled correctly. Severe burns or even death can occur due to the high heat of these liquids when utilized in various applications.

Other negatives include degradation and decreased efficiency over time, which can also release liquid byproducts into the systems and applications they're powering. When water is used as a thermal fluid, for instance, it carries with it the risk of corrosion and contamination, which can be problematic. Another disadvantage is that liquids are often not visible when they enter the heat transfer system.

Thermal Liquid Safety: Mitigating Risk, Protecting Heat Transfer Systems

Thermal liquids tend to operate in fluid heating systems within the equipment. Such heating systems do more than just circulate the liquid, but also control the temperature and allow for prompt cooling. However, the liquids will degrade over time. This can be problematic, as equipment may not perform well over time and byproducts may also enter the system, causing product failure.

The good news is that there are various ways to mitigate risk when working with heat transfer systems, including:

  • Regular sampling: Performing regular, quarterly sampling when the system is live and circulating can help gauge the fluid inside the system and determine its overall quality. After the sample is processed and its condition is determined, additional steps can be taken as necessary.
  • General proactive maintenance: Site surveys and risk assessments handled by third-party vendors can provide an unbiased and valuable overview of a specific site. General housekeeping is important when it comes to preventing accidents in the workplace. Ensuring pathways are clear, materials are properly labeled, and other signage is present as necessary is important to a safe functioning workplace.
  • Remote monitoring: This tactic can significantly boost remote maintenance and provide engineers with real-time data to ensure the safe and efficient use of thermal fluid.
  • Reactive measures: While it's always best to be as proactive as possible, sometimes accidents just happen. And when they do and involve thermal fluid, a prompt response is essential. That's where it can be handy to have spill kits and PPE on hand. Workers should be trained with where such supplies are located so they can act fast in an emergency.

HTF Protective Clothing (and Other Necessary PPE)

It should go without saying that wearing the right PPE is crucial when it comes to handling, sampling, or cleaning up thermal fluids. Below is an overview of the PPE that should be worn when working with such liquids:

  • Eye protection: Eye protection is essential when working with hot, dangerous liquids. Any fluid that splashes into the eyes could cause serious eye damage or potentially blindness. At a minimum, anyone handling thermal fluids should be wearing safety glasses. It's typically a better option to elect to wear a full facemask, which protects more than just the eyes, but the full face from burns as well.
  • Coveralls: When you're working with hot liquids, you don't want them to come in contact with any bare skin. That's why a full body suit is important. Disposable protective coveralls are designed to fit over street clothes to keep the arms, legs, and torso safely covered.
  • Gloves: Coveralls don't typically extend protection to the hands, which is why a good pair of gloves is necessary when working with hot liquids. Such gloves should be non-porous and resistant to fluid penetration. You may also elect to wear an inner glove to offer an additional protective layer.
  • Boots: Finally, boots can help protect the feet and lower legs, while also offering some heat resistance.

Other PPE that may be deemed necessary following a hazard risk assessment includes ear protection, a hard hat, and a respirator.

Thermal Liquid Regulations

The Occupational Health and Safety Administration (OSHA) requires PPE for any short-term exposure to hot liquids. These PPE requirements are noted in OSHA Standard 1910.132.

If you work in a building or industry that relies on thermal liquids, now's a good time to review your safety protocol when it comes to the sampling, handling, or cleaning up of such fluids. Make sure the proper safety measures are in place, your employees are properly trained, and you have PPE for them to use. The right thermal liquid protective clothing can help prevent a serious injury during a routine task.