When using hair straighteners or curling irons, one must apply enough heat to temporarily break the chemical bonds that give hair its natural texture and shape. But if too much heat is used — by way of either a too-hot iron or too-frequent styling sessions — then those chemical bonds can be permanently damaged, resulting in fried hair that loses its natural shape. Contrary to what some advertising might have you believe, there are no primers or protective sprays that can prevent permanent heat damage.
This is becoming more of an issue as women of African descent increasingly chose to forgo chemical straighteners, Reid told The Post. More and more women keep their hair's texture natural, but that means they're at risk of heat damage when they occasionally choose to straighten with tools.
"When you go to hair stylists and ask this question — I mean, I've asked this question myself," Reid said. "When you ask how to avoid heat damage, there's just no definitive answer."
A quick search on YouTube pulls up more than 100,000 videos on the subject, all offering unscientific advice. Even manufacturers of the tools themselves don't agree, with some recommending certain heat ranges for one hair type and others recommending lower or higher ranges.
"I got curious about quantifying the problem," Reid said.
For now, her lab engineers have designed their experiments and will present their initial paper on Monday at the American Society of Mechanical Engineers' International Design Engineering Technical Conference.
Over the next few months, Reid and her colleagues will be using infrared microscopes to study how heat moves through individual strands of hair during the straightening process. Instead of splitting hair into the three groups -- African, Caucasian and Asian -- that previous research has focused on, Reid's lab will categorize by the tightness of curl to get a more nuanced look at damage. The team believes it will find marked differences in the way hair of different textures reacts to heat, even within the larger ethnic categories.
The work has already attracted the interest of some hair-care companies that have since contributed funding, though Reid couldn't disclose which ones were involved. Reid hopes her work will empower women to take control of their hair-styling choices.
"The hope is that a person could make reference to a chart that we can put in their hands, so that they’re clearly able to identify their own hair type, and say 'All right, here is the range of temperatures that have been empirically validated to not damage my hair,' " she said. A lot of hair-care companies will make claims about heat damage prevention as part of a marketing scheme, Reid said, but noted that her group's work seems to be the first objective look at the problem.
"Because we're engineers, the only agenda we have is truth," she said.