The Brazilian Blowout Acai Professional Smoothing Hair Solution could expose people to potentially dangerous levels of the cancer-causing chemical formaldehyde, according to the study in the August issue of the Journal of Occupational and Environmental Hygiene.
"Our study found that using Brazilian Blowout, without proper engineering controls like local exhaust ventilation, could expose hairdressers and their clients to formaldehyde at levels above the short-term occupational exposure limits," study author Michelle Stewart said in a University of California, Berkeley, news release.
She conducted the study as a graduate student in the university's school of public health. Stewart and her colleagues found that formaldehyde concentrations in the air around hairstylists and customers exceeded limits set by the US Occupational Safety and Health Administration, the US National Institute for Occupational Safety and Health, and the California Division of Occupational Safety and Health.
The findings appear in the Journal of Occupational and Environmental Hygiene.
"While installing local exhaust ventilation is a traditional exposure control, that solution may not be feasible in small salons due to the cost of ventilation systems, permits, installations, ongoing maintenance and efficacy checks," Stewart noted.
"The recommendation is that salons use products containing no more than 0.1 percent formaldehyde, but the product we investigated contained 12 percent formaldehyde," she added.
Symptoms that have been reported by hairstylists when using hair-straightening treatments such as Brazilian Blowout include watery eyes, runny nose, upper respiratory tract irritation and nosebleeds. The product is available in more than 6 000 salons within the United States, according to the news release.
The Environmental Working Group has more about hair straighteners.