General Description

Triethylene glycol, a versatile industrial liquid used in various applications, has garnered attention for its effectiveness in air treatment, especially in combatting airborne viruses like SARS-CoV-2. Despite regulatory delays in approving TEG-based products for indoor air disinfection, experts across multiple sectors advocate for its rapid deployment to enhance indoor air quality and mitigate infections. While Triethylene glycol shows low acute toxicity and minimal environmental impact, precautions are necessary during occupational exposure. Overall, Triethylene glycol's ability to swiftly neutralize viruses in indoor settings underscores its importance in public health, urging authorities to expedite its regulatory clearance for broader utilization.

Figure 1. Triethylene Glycol

Overview

Triethylene glycol is a colorless, odorless, viscous liquid with a formula of C6H14O4. It is part of the glycol family, primarily used for its hygroscopic quality, which means it readily absorbs water from the air. This makes Triethylene glycol particularly useful in industrial applications such as natural gas dehydration, where it helps in removing water vapor from gas streams to prevent pipeline corrosion and freezing. Triethylene glycol is also employed in the manufacture of polyester resins and polyurethane foam, as a plasticizer, and as a solvent in various applications. Its effectiveness in capturing airborne bacteria, viruses, and mold spores makes it a valuable component in air sanitization products, contributing to healthier indoor air environments. Furthermore, Triethylene glycol is used in the automotive industry in brake fluid formulations to enhance the fluid's boiling point and performance. In terms of safety, while Triethylene glycol is generally regarded as safe when used in industrial applications, it can be hazardous if ingested, with potential to cause kidney damage. Its handling requires appropriate safety measures, such as wearing protective gear and ensuring good ventilation to avoid inhalation of fumes. ¹

Applications in Air Treatment

Triethylene Glycol stands out as a promising solution in air treatment, particularly in combating indoor airborne viruses like SARS-CoV-2. Unlike some disinfection methods limited to surface application or non-human presence, TEG-based formulations offer a safe and effective means of treating indoor air without disrupting human activities. The efficacy of Triethylene Glycol in killing viruses, including SARS-CoV-2, has been established at low concentrations, making it safe for human exposure. Regulatory agencies, however, have been slow in approving TEG-based products for indoor air disinfection, hindering its widespread adoption and potentially prolonging the pandemic's impact. Triethylene Glycol's safety profile extends to its use in air fresheners and theatrical effects, further supporting its suitability for indoor environments. Unlike alternatives like enhanced ventilation, HEPA filtration, or UV light treatment, which may have gaps in virus-killing effectiveness due to delays in air treatment, Triethylene Glycol can be predeployed to instantly target viruses upon their introduction into the air. This capability minimizes the transmission window, reducing the risk of infection. The urgency to fast-track TEG-based air treatments is echoed by experts across microbiology, clinical practice, chemical engineering, environmental health, and public health sectors. Accelerating regulatory approval for Triethylene Glycol in air treatment is vital for enhancing indoor air quality, mitigating pandemics, and safeguarding vulnerable populations. In summary, Triethylene Glycol's unique ability to swiftly and safely neutralize airborne viruses in indoor settings positions it as a critical tool in the fight against respiratory infections, urging authorities to prioritize its regulatory clearance for widespread deployment. ²

Health Hazards

Triethylene glycol is primarily an industrial liquid with very low acute toxicity levels through various exposure routes. It does not cause skin irritation, sensitization, or significant eye damage upon contact. However, exposure to Triethylene glycol can lead to respiratory tract irritation, particularly with repeated aerosol exposures, resulting in symptoms such as cough, shortness of breath, and chest tightness. While Triethylene glycol does not typically induce systemic or long-term toxicity, such as hepatorenal injury, it can affect kidney function, urine volume, and blood parameters if absorbed in large doses. In terms of developmental toxicity, maternal toxicity was observed in rats and mice at certain dosage levels, but no embryotoxic or teratogenic effects were noted. For environmental impact, Triethylene glycol is considered low in aquatic toxicity and environmental persistence. Protective measures such as gloves, goggles, and proper ventilation are recommended during occupational exposure to Triethylene glycol to prevent adverse health effects. Overall, Triethylene glycol poses limited hazards to human health and the environment when used and handled appropriately. ¹

Reference

1. Triethylene Glycol. National Center for Biotechnology Information. 2024; PubChem Compound Summary for CID 8172.

2. Goldman E, Choueiri TK, Mainelis G, Ramachandran G, Schaffner DW. Triethylene Glycol Can Be Predeployed as a Safe Virus-Killing Indoor Air Treatment. J Infect Dis. 2022; 226(11): 2040-2041.