Antimicrobials in Gyms—Health Help or Harm?

January 17, 2024

When you go to a gym, you expect to leave healthier than when you came in. Many gyms ask patrons to wipe down equipment after each use to keep it clean. However, most patrons and gym managers have not put much thought into the chemicals found in the sprays and wipes used at their gym. Are the chemicals safe and are these products effective?

We decided to investigate. We visited our local gym and looked for the label on the spray bottle. To our surprise, the label listed several chemicals of concern called QACs or Quaternary Ammonium Compounds. These strong chemicals are intended to disinfect surfaces and need to be left on precleaned surfaces for several minutes to kill germs.

Our Institute recently published a review paper entitled “Quaternary Ammonium Compounds: A Chemical Class of Emerging Concern” with 24 expert authors, on the potential for harm of QACs. The paper cited studies showing that QACs can contribute to skin, lung, immune, reproductive, and developmental health harm. These chemicals also contribute to antibiotic resistance—a serious and growing global health problem.

Unfortunately, use of QACs in products has been growing ever since 2016 when the FDA banned 19 other commonly used antibacterials from use in over-the-counter soaps and body washes—and QACs were the main replacements. The COVID pandemic led to further increased use of QACs in wipes, sprays, and foggers, even though they are rarely used as directed.

More is not always better when it comes to things like disinfectants and antimicrobial additives in cleaning products. Soap and water, other surface cleaners, or wiping down the equipment with cloth are more effective at removing dirt and grime.

Disinfectants are only recommended for use in food preparation, sanitation, and medical settings. In other settings, the use of these harmful chemicals creates unnecessary exposure for people and the environment.

We wondered if all gyms were using unnecessary disinfectants, or if our gym was an outlier. We asked Maya Carpenter, our enthusiastic summer intern, to visit gyms in the San Francisco Bay Area and report on what gym patrons were using to spray or wipe equipment. Her findings were concerning. Over half the gyms requested their customers use QAC on the equipment after each use. However, several gyms used alternative disinfecting solutions, such as hydrogen peroxide, ethanol, and citric acid, which may be more effective and safer than QACs.

To be effective, QACs need to be applied to a clean surface and left wet for several minutes before being wiped clean. Research has shown that improperly used antimicrobials can lead to the survival of only the strongest bacteria.

Since no one is waiting minutes between spraying and wiping down the equipment the improper use of these disinfecting products in gyms could be contributing to antibiotic-resistant pathogens. We have also observed gym users spraying the equipment with lots of the QAC-based solution, then wiping it up immediately with a towel, and then wiping their foreheads with the same towel. This behavior both fails to disinfect the equipment and exposes the patron to a large dose of harmful chemicals. Furthermore, after QAC solutions dry on surfaces, they leave behind a solid residue that exposes patrons to the QACs long after use. This residue can transfer to the skin, clothes, or hair of gym goers, continuing their exposure long after they leave the gym.

The gyms we spoke to were spending $100-200/month on concentrated chemical solutions that are not currently being used as directed. This is leading to unnecessary chemical exposure for patrons and employees without providing the intended protection. We believe it would be more effective to use dilute solutions of soap and water or damp rags to clean away sweat and dirt on gym equipment after use.

If serious disinfection is desired for wrestling mats or other equipment at the end of the day, it should be carried out by employees who are trained to use the disinfectant chemicals properly and know how to protect themselves from exposure. Here is a list of disinfectants with safer active ingredients from Toxic Use Reduction Institute in Massachusetts.

There are over 40,000 gyms and health and fitness clubs in our country and based on our survey it is likely that many of them are using ineffective and unnecessary QAC disinfecting solutions. By switching to simpler cleaning procedures and only using safer disinfectants on an as-needed basis, gyms could save $1,000s per year and provide a safer cleaner environment for patrons.