Sink or Swim: The Hidden Danger of Swim Caps

Swim Caps CEH

Center for Environmental Health (CEH) finds cancer-causing chemical in Swim Cap

In the fleeting moments, before the Olympic Swimmers take their marks, their brains race through all their training, mental preparation, and previous races. The last aspect of the race they should be focusing on is the swim caps on their head. This year has been a tumultuous experience for many Olympians and dedicated viewers alike. Earlier in the season, The International Swimming Federation (FINA) outlawed the use of SoulCaps which are designed to help contain more hair for swimmers of color. This decision reflects a lack of access and an intent to maintain barriers to entry for non-white swimmers. This year, what swimming caps are made of may be just as alarming as our policies regarding them. 

The Center for Environmental Health (CEH) recently found evidence of a Speedo latex swim cap containing dangerous levels of a nitrosamine chemical – Nitrosodiethylamine, or NDEA. NDEA is reported by the State of California Office of Environmental Health Hazard Assessment (OEHHA) to contain cancer-causing materials. 

CEH commissioned independent lab testing and found that a Speedo cap had levels of NDEA present that would expose a user to more than 3,000 times the daily safety standard for NDEA under California law. Swimmers can be exposed to NDEA through the skin, as the chemical can leach from the material when a swimmer is wearing it. The chemical is known to cause cancer in diverse organs and tissues including lung, brain, liver, kidney, bladder, stomach, and esophagus. 

CEH has initiated legal action under CA Proposition 65 against Speedo, asserting that the company failed to warn swimmers of potential exposure to NDEA. For over 30 years, Prop 65 has served as a safeguard for consumers, protecting their right to know if a toxic chemical may be in a product before it is purchased, or serving as incentive for companies to remove concerning chemicals from their products so that they do not have to warn the buyer. 

This same chemical was found in popular workout bands earlier this year by the Center for Environmental Health. “As someone who uses resistance bands, this issue is personal,” said Emily Reder, the Research Manager at CEH who led the testing. “No one should be exposed to carcinogenic chemicals, especially from products marketed to help improve your health.” CEH is hopeful that defendants in both latex product cases will choose to make their products safer for consumers by removing NDEA altogether, rather than simply adding a label and continuing to sell a product with a known cancer-causing chemical.

The presence of NDEA is not just concerning for our most talented athletes in the world. Swimmers everywhere, from youth to Olympians, use latex Speedo caps every week. Our athletes of all ages are being exposed to a chemical known to cause cancer in diverse organs and tissues including lung, brain, liver, kidney, bladder, stomach, and esophagus. Athletes should not have to worry that their commitment to their sport may potentially harm them later in life. Mainstream products like these are an active threat given their use in sports and normalization across leagues. 

Kathryn Alcantar, Policy Director at CEH, said her 9-year-old daughter swims on a local team where youth use caps 4-5 times a week. “I was shocked to find out that I could be harming rather than helping my daughter’s health by sending her to swim practice with her swim cap,” said Alcantar. “Speedo should remove this toxic chemical and move to safer alternatives for the health and safety of our children–and all athletes.”

When I was younger, one of the most popular sports in my town was competitive swimming. I swam for my local team for only a few years. My memories of that time are filled with warming jackets, hot chocolate, and the many Speedo swim caps that were in my top drawer. It is quite alarming to look back on fond memories of that era of my life and realize that most of us may have been exposed to toxic chemicals up to four times a week. Children should not be exposed to harmful toxins that could drastically change their lives in the future. 

NDEA is listed on the OEHHA Proposition 65 list and is a firm reminder that this critical right-to-know law provides us with information that could potentially change our lives. If Olympians like Katie Ledecky, or 8-year-old me, had access to information about the potentially harmful products in our swim caps, we likely would have used alternative brands. Prop 65 and its partners use these labels to ensure that consumers, athletes, and families have access to the information they need to make health-protective purchasing decisions. Moving forward, we can hope that Speedo, and work out bands like it, reformulate their products to be safer.