Problems with Optical Brighteners

Many laundry detergents promise to make your white clothes whiter than white. How do they do this? Using chemicals called optical brighteners.

What are optical brighteners?

Optical brighteners are chemicals that absorb ultraviolet light and reflect back blue light. This helps to hide the normal yellowing of white clothes, and makes them appear whiter and more vibrant. Optical brighteners add chemcials to your clothes, rather than removing stains from your clothes. You could call it an optical illusion.

What are optical brighteners used for?

Optical brighteners are most commonly used in laundry detergents. But they’re used for lots of other things as well. You can find optical brighteners in small amounts in products like cosmetics, cotton balls, and fabrics. Paper products, like food packaging, printer paper and toilet paper often use optical brighteners. You can find optical brighteners in just about anything that you might want to look bright white.

What’s the problem with optical brighteners?

In the 1970s, scientists studied the effects of optical brighteners on the environment, and on humans. This research showed mixed results.

Skin Allergies: One study found that contact with optical brighteners can cause an allergic reaction called contact dermatitis. The symptoms are red, itchy, irritated skin.

However, further studies on this effect were inconclusive. Researchers found no immediate danger, but they haven’t ruled it out. To confirm whether the material is completely safe or not, scientists need to do further research.

In 2002, one study found a skin reaction to optical brighteners in less than 0.7 percent of over 3,000 participants. So, a reaction may be possible, but it’s very rare. This study also had inconclusive results.

Environmental Effects: One Swedish study claimed to have found that optical brighteners cause genetic mutations in fish and plants. Later studies were unable to replicate these findings, and the results were, again, inconclusive.

We do know one thing for sure about optical brighteners: they’re not biodegradable. Bacteria can’t break down optical brighteners in the environment. Non-biodegradable materials can stick around for hundreds of years, polluting the environment and leaching toxic chemicals into the soil and water.

Optical brighteners are so commonly found in wastewater that scientists use them to detect whether bacteria is contaminating community water supplies. This water flows into rivers, streams and oceans, and into the ground, and optical brighteners go right along with it. And because they’re not biodegradable, they won’t go away.

Inconclusive Studies: Meanwhile, scientists are still conducting studies to decide if optical brighteners are safe or not. In the U.S., the Food and Drug Administration sets limits on the amounts of brighteners allowed in food packaging products. The FDA cites inconclusive studies as a reason for these precautions.