Cold Chemical Sterilization for Dental Settings

Cold Chemical Sterilization for Dental Settings

Dental facilities are a place where patients should feel safe while they receive essential healthcare. Although heat-resistant plastic instruments are quickly moving to the forefront of the dental industry, there are still some situations where alternative reprocessing methods are required. Cleaning patient care equipment and ensuring it is safe for patients is an essential part of dental healthcare providers’ responsibilities. In some instances, cold chemical sterilization is necessary to ensure heat-sensitive tools are properly prepared and safe for reuse on patients.

What Is Cold Chemical Sterilization?

Cold chemical sterilization is a popular process among many medical professionals. It is a method that requires the sanitization of reusable instruments using liquid chemicals approved for (chemical) sterilization by the FDA. The contaminated instruments are immersed in a chemical solution to achieve chemical sterilization.

This specific sterilization process is often referred to as “cold” sterilization because it best applies to heat-sensitive instruments that are unable to withstand the much higher temperatures of dry heat sterilizers and autoclaves. An autoclave is a heated container where chemical reactions can occur, resulting in the highest microorganism kill levels possible. Cold chemical sterilization should never be performed on single-use instruments or devices.

Since the cold chemical sterilization method lacks the intense heat present in an autoclave or dry heat sterilizer, it’s not quite as effective. While the level of sterilization is significant in the cold chemical process, heat sterilization is always preferred. There are benefits to the method, but it also has considerable drawbacks.

What Chemicals Are Used in the Sterilization Process?

There are three types of chemicals typically used in the cold sterilization process. The following substances have all been approved and cleared by the EPA and FDA for use in dental settings:

  • Glutaraldehyde (the most common chemical used)
  • Ortho-phthalaldehydes or OPA
  • Hydrogen peroxide solutions
  • Peracetic acid

The go-to chemical sterilant for most medical facilities is glutaraldehyde. There are some environmental and health concerns surrounding using cold chemical solutions, despite multiple federal agencies’ safety designations. Health concerns include monitoring the permissible exposure levels (PEL) and respiratory effects from chemical vapors. Proper disposal is a primary environmental concern.

Cold Chemical Sterilization Concerns

While the use of cold chemical sterilization is still widespread in dental settings, many industry professionals question its efficacy and safety. The U.S. Centers for Disease Control and Prevention (CDC) have voiced considerable concerns about using this method in medical, dental, and other healthcare-related settings. The CDC and the American Dental Association (ADA) discourage using cold chemical sterilization.  These organizations recommend using this method only if other alternative instruments or devices are not available on the market.


The method used for cleaning dental instruments must be effective in ensuring the safety of your patients. The CDC continually recommends that medical and dental facilities use heat sterilization methods whenever possible. Although cold sterilization holds some merit for individual instruments and instances, it’s not nearly as effective as its much hotter alternative, the sterilizer.

Science has proven that heat is the most effective method of penetrating barriers beyond biofilm and blood to kill harmful bacteria and organisms. There is no straightforward way to measure the effectiveness of the cold chemical sterilization process. For this reason, the CDC limits dental facilities’ use of liquid chemical sterilants.

Safety Concerns

Additionally, the cold sterilization method has potentially severe environmental and health effects. The process includes using potentially harmful substances corrosive to human skin, so dental workers must take serious precautions during the entire procedure. When utilizing the cold chemical sterilization process, dental workers should always:

  • Wear chemical-resistant gloves when handling instruments around and in the chemical solution.
  • Wear safety goggles or glasses near the solution to protect against any splashing.
  • Avoid using cold chemical sterilization for any instruments that can undergo the heat sterilization process instead, as it can cause damage to the tool.
  • Regulate the disposal methods for the sterilization solution, providing chemical neutralizers as necessary.
  • Work in a well-ventilated area when handling chemical solutions.
  • Keep covers on the containers holding the chemical solution and instruments to avoid evaporation.

Dental facilities should always ensure the availability of proper personal protective equipment (PPE) for all people, especially those working with dangerous chemicals. Some state environmental agencies are beginning to regulate the use and disposal of glutaraldehyde solutions due to safety concerns. Overall, the process provides unnecessary exposure to a dangerous substance when alternative sterilization methods are available.

Other Cold Chemical Sterilization Issues

Another problem often discussed concerning the cold chemical sterilization process is the extended time required to achieve adequate sterilization of instruments.  Instruments need extensive time in the solution to achieve an acceptable level of biocidal activity for use in the dental setting. Heat-sensitive tools may require up to ten hours in a sterilization solution.

The time each instrument spends in the solution must be timed. If new devices are added to the mix, dental professionals must restart that time. It’s challenging to keep track of how long each singular instrument spent in the solution, so many facilities wind up waiting until the end of the day to add all their used tools at once. This means that tools must sit overnight in the solution, which can be detrimental to their efficiency during procedures.

Benefits of Cold Chemical Sterilization

Although there are certainly some serious concerns regarding the safety and effectiveness of the cold sterilization process, it still has its place in the dental industry. While the CDC has placed limits on the use of cold sterilization in dental settings, it’s still useful for specific procedures, like reprocessing heat-sensitive instruments.

Since sterilization of heat-sensitive patient care items requires extensive immersion periods, it is typically used only when no other acceptable alternate instrument exists for semi-critical instruments,.

The Conclusion of Cold Chemical Sterilization

In recent years, cold chemical sterilization has played a smaller role in the dental community. With more precise heat sterilization procedures, disposable instruments, and heat-tolerant tools and devices, the process is less necessary in the dental industry. However, cold chemical sterilization is still useful in certain circumstances when applied appropriately and accurately. If you feel the techniques used in your facility are outdated, contact an infection prevention expert to implement a more robust process.