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How to Prevent Indoor Off-gassing in Plastics Processing Plants

Take these precautions to protect your workforce from harmful indoor off-gassing.

Kevin Maple

May 22, 2024

5 Min Read
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At a Glance

  • Indoor off-gassing occurs when volatile organic compounds (VOCs) are released into the air during plastics production.
  • VOCs also can be present in the water used during plastics processing.
  • Prevention measures include using plastics with low VOC counts, increasing ventilation, and installing filtration systems.

The plastics industry is one of the most demanding and lucrative in the world. People use plastics in a range of things, including everyday products, construction goods, and more. The process of producing plastics can put workers at risk because of the soft and malleable nature of plastics. In addition to posing a threat to outdoor air pollution, plastic pollution can also be unsafe indoors because of the potential for off-gassing.

Indoor off-gassing, a form of plastic pollution, poses risks to individuals involved in plastics production. This process, also referred to as out-gassing, occurs when volatile organic compounds (VOCs) are released into the air during plastic processing and production. According to the EPA, “VOC is any organic compound having an initial boiling point less than or equal to 250°C measured at a standard atmospheric pressure of 101.3 kPa.” When occurring in significant amounts or over extended periods, indoor off-gassing can present potential dangers.

There are ways to control off-gassing and minimize employees' exposure to it. This article will examine those ways and how to maximize indoor air quality while minimizing air pollution.

What exactly is indoor off-gassing?

As we briefly mentioned, indoor off-gassing involves the VOCs present in plastics. When the plastic is exposed to high temperatures, which is essential during plastics processing and production, the VOCs can bleed away from the plastic. Because VOCs are light and microscopic, they can float into the air and reduce indoor air quality. This process is known as off-gassing.

Why does off-gassing happen during plastics processing?

The primary reason for off-gassing during plastics processing is the reliance on heating the plastic to high temperatures, which can lead to the release of VOCs. The process of heating plastics to shape them into products is commonly known as thermoforming. This process entails heating a thermoplastic material to a pliable forming temperature, shaping it, and then cooling it to retain the desired shape. For polycarbonate, thermoforming typically occurs between 300 and 500°F. Thermoforming finds widespread use in manufacturing various products such as packaging, automotive components, consumer goods, and more.

Additionally, other sources of off-gassing stem from the machinery and equipment used during plastics processing. The main culprits include sanders, die heads, and extruder hoppers because they handle plastics in their rawest state. As these tools work on the plastic, they can cause VOCs to vaporize and be released into the air.

VOC risks with water.

While off-gassing is indeed the most common and well-known method by which VOCs are released into the atmosphere, it is not the sole contributor. Alongside heat, substantial quantities of water are also employed in the processing and production of plastics. 

VOCs can potentially be present in the water used during plastics processing. Thus, it is imperative to implement appropriate water treatment and filtration measures to prevent contaminated water from entering the water supply.

How to implement effective air ventilation during plastics processing.

Because of the health risks associated with indoor off-gassing, it's important to take measures to remove particles from the air and cleanse it. Here are several ways to do just that.

Use plastics with low VOC counts. Plastics with low outgassing include PEEK, PTFE (Teflon), PVDF, Vespel, and Halar (ECTFE). The plastics industry continues to improve materials to lower the risk of VOCs. However, because these plastics can be more expensive and difficult to access, this isn't always a viable option.

Increase ventilation. Another option if you can't change plastics is to increase the ventilation in your building. By maximizing the amount of air that's circulating and the amount of outdoor air that is entering your building, you will minimize exposure to VOCs.

Use better filtration. The best way to reduce and eliminate off-gassing is to use better air/liquid filtration systems. This includes installing water filtration systems that remove VOCs from the water used in plastics production, as well as installing a quality air filtration system that captures VOCs, eliminating them from the air. 

Sourcing the best filtration systems to prevent off-gassing. 

Activated carbon filters are stalwarts in the battle against indoor off-gassing. These filters operate by utilizing activated carbon, which boasts a vast surface area with countless pores capable of adsorbing VOCs present in both air and water. Their effectiveness lies in trapping VOC molecules as they pass through, preventing their dispersion into the environment.

Reverse osmosis systems employ a semi-permeable membrane, filtering out impurities, including VOCs, and leaving behind purified water. When coupled with activated carbon filters, reverse osmosis systems provide a comprehensive solution, ensuring minimal VOC contamination in water supplies.

HEPA and carbon filter combinations are a dynamic duo for combating airborne pollutants. HEPA filters excel in capturing minuscule plastic particles suspended in the air, while carbon filters effectively adsorb VOCs and other airborne chemicals. Together, these filters synergize to deliver high indoor air quality, crucial for maintaining a safe working environment.

Additional benefits of reducing indoor off-gassing.

In addition to preventing serious health risks to your workers, reducing indoor off-gassing has economic and environmental benefits.

  • Less off-gassing means better indoor air quality and fewer health problems for your workers.

  • Healthier workers mean fewer sick days and increased longevity for each employee.

  • Ensures compliance with federal regulations regarding indoor air quality, such as the Clean Air Act.

Solving the problem of off-gassing.

While off-gassing can be dangerous for those involved with plastics processing, it's controllable with the proper filtration and safety measures in place. Modern filtration systems and regulatory guidance can ensure safe conditions for workers and the environment.

Ensuring safety requires maintaining optimal indoor air quality and minimizing exposure to off-gassing. This entails implementing high-quality air- and water-filtration systems and seeking alternative low-VOC plastics and processes. The well-being of employees should always be the foremost priority.

About the Author(s)

Kevin Maple

Kevin Maple is director of marketing at Harrington Process Solutions, a national distributor and supplier of industrial process products and solutions. He has been a critical part of the Harrington team for more than a quarter-century, providing marketing strategy within the industry. Maple has in-depth knowledge and understanding of piping, fluid handling, instrumentation, and high-purity applications.

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