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What Chemicals Are in UV-Protective Rash Guards or Swim Shirts?

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Some UV-Protective rash guards are treated with harsh chemicals. Here's how to avoid them.

Some UV-Protective rash guards are treated with harsh chemicals. Here's how to avoid them.

In order to avoid chemical exposure to toxic ingredients in topical sunscreen, many people have opted to cover up with some sort of UV-protective clothing for protection from the sun. The most popular type of UV-protective wear is the rash guard or swim shirt. These can be effective in protecting skin from sun damage, but they are especially convenient for kids. However, UV-protective fabric may still be treated with chemicals in order to induce this protective effect. The good news is that chemical-free options do exist.

What Is the Difference Between UVA and UVB Light?

All fabric has some level of sun protection; the evidence of sun damage being burn or tan lines. Exposed areas that have been burned show sun damage caused by UVB light. The areas protected by fabric seem like they have not been damaged, however, UVA light penetrates through clothing and deeper into the skin, causing long-term damage such as wrinkles and skin cancer without causing a sunburn.

Those with medium or darker skin are naturally more protected against sunburn but can still benefit from protection against UVA rays.

UVA rays penetrate clothing and deeper into skin than UVB, causing aging and cancer. UVA light does not cause a sunburn and is not easily blocked by topical sunscreen.

UVA rays penetrate clothing and deeper into skin than UVB, causing aging and cancer. UVA light does not cause a sunburn and is not easily blocked by topical sunscreen.

Sunscreens Are Inadequate Sun Protection

Experts agree that UV-protective clothing provides a more thorough and reliable shield from the sun compared to sunscreen, which has proven to be inadequate. It's better for your skin to wear clothing that provides a complete block against UV rays.

In the past, sunscreens have been rated for protection from UVB light only. The SPF rating is based on prevention of sunburn. However, labeling requirements are changing to show a sunscreen's effectiveness for both UVA and UVB rays. Sunscreens that are effective in blocking UVA rays tend to be thicker since they contain blocking ingredients like zinc oxide. For this reason, many people don't like using them. To avoid chemicals and questionable sunscreen labels, covering up with some sort of UV-protective clothing seems like the easiest and surest way to avoid real sun damage.

What Is UPF?

Based on the knowledge that specific fabrics are better at providing effective sunblock, companies are designing UPF-rated clothing that is lightweight, comfortable, and protective. The UPF rating measures the UV radiation that penetrates fabric to reach and penetrate the skin. Some of these products are treated with a chemical additive to create the protective effect, but with new innovations, this is an unnecessary health risk.

Look for certain fabrics that have UV protection.

Look for certain fabrics that have UV protection.

Fabric With UV Protection

Different kinds of fabric are more effective than others in blocking UVA and UVB light. The only way to know for sure if fabric offers UV protection is if it's been UPF tested (ultraviolet protection factor). Here are some general rules to help determine how much sunlight clothing can block.

  • Tighter-weave fabric blocks more light. By holding fabric up to light you can see how much light gets through.
  • Dyes in fabric absorb UV rays. It is not necessarily darker colors that are more protective, but more dependent on the type of dye used. Lighter colors reflect more light, but it's visible light that's being reflected, not damaging UV rays.
  • The weave of the fabric matters. Cotton is the worst-rated protective fabric whereas synthetic fabrics like polyester and nylon absorb more UV rays.
  • Thicker fabrics have a more protective effect.
  • Wet fabric loses protectiveness.
  • Fabrics that have more stretch tend to have less UV protection. As the fabric is stretched, space develops within the weave.
RatingProtective Effect

UPF 15-24


UPF 25-39

Very Good

UPF 40-50+


Chemical-Free Swim Shirts

If you're looking for a chemical-free swim shirt or rash guard, then you will want the nature of the fabric itself to be what makes it protective. Tightly woven fabrics made of polyester or nylon are naturally nonabsorbent and quick drying without the need for chemical treatments to be UV protective.

The clothing will likely still be processed using dye and color-setting chemicals so the term chemical-free refers to the product being free of chemicals to induce the UV protective element. Even with that said, claims that swimwear is chemical-free may just tell us that the item is not processed with chemicals once it's made, but it still may need some sort of treatment to help with the UV protectiveness in early stages of processing the yarns, especially for lighter colors.

Be careful of misleading claims—online searches for chemical-free swim shirts will result in ads that claim their swimwear is chemical free when they are just referring to the swimwear as an alternative to chemical sunscreen.

Why Should You Avoid Chemicals Like Optical Brighteners?

It's difficult to discern exactly what chemicals are being added to fabrics to create UV-protective clothing. Optical brighteners (also known as brightening agents), optical whiteners, or fluorescent bleaches are a few types of chemicals used to make swim shirts. The EPA states that optical brighteners are potentially toxic to humans since they are suspected of causing adverse reproductive and developmental effects.

Optical brighteners are a type of dye that absorbs UV light and reflects back blue visible light, which tricks the eye into making colors seem brighter. Note that this ingredient is also present in many laundry detergents to make whites seem whiter and brights seem brighter without actually making them cleaner.

Just as optical brighteners bind to fabric, they also bind to skin, which can't be good for the skin. Couple this with the fact that when optical brighteners break down after being exposed to sunlight, a phototoxic skin irritation or a photoallergy can develop. Many sensitivities that are blamed on dyes or fragrances may actually be due to optical brighteners. In addition, long-term safety testing has not been performed.

Environmentally, optical brighteners are not friendly. They are toxic to fish, algae, and other plants. They can bioaccumulate in larger fish and are not readily biodegradable. Optical brighteners have even been shown to cause mutations in bacteria. Pollution caused by optical brighteners through laundry and treatment of UV-protective clothing is detrimental to water quality and water habitats.

Rash guards and swim shirts for kids protect skin from sun damage caused by UVA and UVB rays.

Rash guards and swim shirts for kids protect skin from sun damage caused by UVA and UVB rays.

Who Is Most Vulnerable to UV Skin Damage?

Vulnerability to skin damage by UV radiation varies based on several factors. The following increase your risk:

  • light/fair skinned
  • proximity to the equator
  • higher elevations
  • activities involving reflective surfaces such as water, sand, or snow (up to 85% of the sun's damaging rays are reflected back by these surfaces)
  • younger ages—accumulating exposure during early years is most damaging

Example: Fair-skinned individuals living in Australia and participating in water-related activities have a high level of risk and have been pioneers in using sun protective clothing.

Where to Buy Chemical Free UV-Protective Swimwear

I contacted several companies to find out the details. Based on my research, below are the companies where I would shop to purchase chemical-free UV wear. The following places also carry products for the entire family, including swimwear, hats, clothing, and other accessories.

Regardless of your skin type, UV-protective clothing is your best method for protecting your skin from damage caused by UV radiation. Find fabrics that are made specially to protect you from the sun without added chemicals like optical brighteners, which can be harmful to your health. Even if it's difficult to figure out if the UV clothing is actually chemical-free, choosing a tight weave, dark-colored, synthetic material from a company that claims that the item is not treated with chemicals is your best bet. The worst case is that you are avoiding using sunscreen lotions that are not reliably providing full UV protection. Swim shirts and rash guards with high UPF ratings are good for the skin and better for the environment.

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2012 Melis Ann


Melis Ann (author) from Mom On A Health Hunt on April 01, 2015:

Hello RTalloni - you are welcome. I hope you can make some good decisions based on the chemical content of sun protective clothing with this information.

RTalloni on April 01, 2015:

So appreciate this post on safe clothing that provides sun protection.