The risk is most prominent when the flat iron is fully heated, noted the experts, as this is when formaldehyde is released as a gas, causing the eyes, nose, and throat to become irritated.
“In more severe terms, long-term exposure to formaldehyde has been related to an elevated risk of cancer,” adds Penn University.
Although the potentially harmful side effects of these habits should not be ignored, Doctor Charlotte Woodward pointed to the other clues of ill-health that hair can reveal.
People with thyroid problems commonly contend with changes in the appearance of their hair, as well as shedding, explained the expert.