Personal care products, and especially haircare items such as shampoos and sprays are not just for looking good. These products quietly release clouds of toxic chemicals in your home. They include volatile substances that react with the air to form new compounds, which can affect indoor air.
It turns out that almost everyone uses hair products. In a European study, 97% of respondents used them, and many applied them every day. Scientists used a sophisticated chemical sniffer to look into the air while styling. They found siloxanes and terpenes as well as glycols.
Purdue University’s new study has revealed that styling your hair with heated appliances like straighteners and curlers does not only release fragrance into the atmosphere. Your hairstyle creates billions of nanoparticles that can penetrate deep into the lungs.
Researchers say that these particles, which range from 6 to 50 nanometers in size, can be so dense during an average 10-20-minute routine, it is like being stuck in heavy traffic.
Researchers have found that 10-20 minutes of heat hair styling can cause the release of over 10 billion nanoparticles into the air. Many settle in the lungs, causing respiratory distress, inflammation and cognitive decline.
This is a very serious matter. Nusrat J., assistant professor at the Lyles School of Civil and Construction Engineering. The number of nanoparticles that are inhaled by using hair products purchased at a store is far higher than what we expected.
The study, published in Environmental Science & Technology is the first one to show real-time measurements of nanoparticles during residential heat styling. Using sophisticated instruments in a lab specially built called the zEDGE small house, researchers tracked the rapid transformation of volatile chemicals such as D5 siloxane – a common hair product ingredient – into nanoparticle clouds when heated above 300degF.
D5 siloxane accumulates and is not easily broken down. In the EU, it’s restricted for use in wash-off products because animal tests showed that the chemical can be harmful to the nervous system, lungs and liver.
Here’s the twist, though: When heated (think straighteners or curling irons), D5 turns into nanoparticles that are airborne. Scientists are still unsure of the long-term impact these tiny particles have on your health. It’s possible that the invisible cloud created by your hair styling is more than just a fragrance. Scientists are still studying its long-term effects.
The particles are dangerous because the body cannot protect them and they lodge deep in the lungs. Liu, co-author of the study, said that “heat is the primary driver.” It triggers a chemo-chain reaction, which turns grooming everyday into an event of high exposure.
One hair-styling session can produce over 10 billion particles, the majority of which settle deep inside your lungs in the region called pulmonary, making them difficult to remove.
Animal studies, however, have shown that D5 siloxane can cause damage to the liver, respiratory system, and nervous systems. In the EU, it is prohibited for use in wash-off products due to bioaccumulation and persistence.
Jung and Liu suggest that to reduce the exposure, you should avoid heat styling or improve ventilation by using fans when doing your hair. Even without heat, improved airflow helps reduce chemical accumulation. Liu said.
The team hopes that future research will dig into the composition of the tiny particles and their health impacts. Your hair may look good, but you could end up paying the price for it.
Journal Reference
- Jianghui Liu, Jinglin Jiang, Satya S. Patra et al. Indoor Nanoparticle Exposures and Emissions During Heat-based Hair Styling Activities. Environmental Science & Technology. DOI: 10.1021/acs.est.4c14384
