Toxic tradeoff: Disinfectants are ineffective for COVID-19 prevention and create harmful exposures

September 19th 2022 | Published by the Healthy Debate

By now you have probably read about the efforts to “clear the air” to prevent airborne transmission of the virus that causes COVID-19. There are countless health and other benefits to improving indoor air quality, not least of which is the prevention of this multi-system virus that has altered the shape of our lives over the past three years.

Early recommendations to prevent COVID-19 focused on handwashing and disinfecting surfaces as we did not understand how the virus was dominantly transmitted: through aerosols floating in the air. Over time, recommendations and mandates included the need for masking and, as they became available, the promotion of vaccines as integral parts of public-health messaging. With the evidence that has accumulated, we know that a layered approach to virus prevention is necessary. Surface cleaning will not protect us.

Not only is overzealous cleaning ineffective at eliminating COVID-19 transmission, but there are potential adverse health impacts of toxic exposures from the ubiquitous use of disinfectants and cleaners. Furthermore, these substances are linked to many adverse human health outcomes. And these may be even greater for children.

There is widespread use in schools of disinfectants and cleaners, some of them containing quaternary ammonium compounds or “quats” and other harmful components. What is not so widespread is the knowledge of the health harms to children, educators and staff in the education system who use and are exposed to them.

Robust scientific evidence on the negative health impacts of “quats” and other chemical compounds in cleaning products and disinfectants suggests we should avoid or limit their use. Short-term effects include:

  • irritating, itchy or burning eyes;
  • skin rashes, allergies and burns;
  • dizziness and headaches;
  • nose bleeds;
  • sore throat, coughing, wheezing, and shortness of breath.

Research shows that, depending on the chemical composition and depending on exposure at critical windows of vulnerability that might include age, stage of development, sex or gender, exposures can lead to longer term harms. Many of the known and suspected health harms are serious and can impact quality of life significantly. Adverse health outcomes include:

  • asthma;
  • harm to the brain, nervous system, reproductive organs, kidneys and liver;
  • endocrine disruption, reproductive toxicity, harm to sperm quality reduction in fertility and birth anomalies;
  • cardiovascular problems;
  • cancer.

At the same time as we contend with the ongoing pandemic, the federal government is considering Bill S-5, an amendment to the Canadian Environmental Protection Act, the cornerstone legislative framework for toxics control. Foundational to this piece of health and environment legislation is a framework for toxics assessments. The assessment process provides for the re-examination of substances that are thought to be toxic based on evidence brought before the minister. An assessment process that finds toxicity can lead to a safe substitution of that product with another one that presents a lesser risk. Substitution with available safer products or practices is critical for public health.

Furthermore, the bill would for the first time bring into Canadian law the right to a healthy environment. Who would dispute the right of our children and indeed all of us to a healthy environment? We cannot claim our education settings are considering this to be a right when we are allowing unnecessary and widespread use of harmful chemical disinfectants and cleaners.

Since schools are also workplaces – a fact that is so often overlooked – it is important to consider occupational health and safety implications as the exposures may be higher for staff who are using these substances in high volumes. Under the occupational health and safety hierarchy of controls (see figure below), action is to be taken that prioritizes the elimination of substances where they are harmful. In the case of mitigating the risk of COVID-19, this would mean eliminating toxic cleaners and disinfectants and instead clearing the air with improved ventilation and filtration, as well as strongly recommending respirator-style masks for all.

Improved ventilation would have the additional benefits of removing toxins from the interior building air, reducing CO2 levels for improved cognition and addressing off-gassing of other substances from the built environment including PAHs, PFAS, phthalates and other volatile chemicals.

While mitigating the risk of COVID-19 and other viruses, we must be diligent about all health threats in the places we live, work and play. Avoiding all toxic exposures is good policy. The evidence that COVID-19 is airborne coupled with the science of harms associated with substances found in disinfectants and cleaners necessitates clearing the air for illness prevention. We should not have to make a toxic tradeoff.

Decision-makers in schools and all our public spaces must take action with the aim to be both virus free and toxic free.

Figure by WorkSafeBC
Photo by Maridav/