Kidney risk after Brazilian straightening: authorities sound the alert on a toxic ingredient

Kidney risk after Brazilian straightening authorities sound the alert on

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    Widely used by hairdressers to straighten their clients’ hair, Brazilian straightening is in the sights of health authorities. In question, a “potentially toxic” ingredient responsible for kidney failure: glyoxylic acid.

    In a press release published this Wednesday, ANSES recommends against the use of “Brazilian straightening” type hair products containing glyoxylic acid. The reason: its “potentially toxic” nature for the kidneys.

    Four cases of acute kidney failure occurring in France

    This alert follows the report of “four cases of acute kidney failure, linked to the use of different hair products containing glyoxylic acid” occurring in France, according to ANSES. Four people were poisoned between January and August 2024. Three of them were treated while “the last is still hospitalized”.

    This is not the first time that this type of product has been singled out. A clinical case, which we told you about in a previous article, has already been revealed by a French team and published in the medical journal The New England Journal of Medicine, last March. This time, health authorities decided to tackle the problem head on, believing that other cases may have slipped under the radar.

    What are the symptoms of poisoning linked to a straightening product?

    According to Dr Juliette Bloch, director of health alerts and vigilance at Anses who responded to AFP, kidney damage is caused by glyoxylic acid following the passage of the substance into the blood, “through the scalp” .

    Side effects which theoretically should not occur, the product not being deposited directly on it during straightening. But only in theory, because contact does take place, particularly during the rinsing stage.

    If you have just done straightening and you feel, in the hours or days that follow, abdominal or lower back pain, nausea and/or vomiting, you should quickly consult a doctor or call a poison control center.

    An expertise was launched by ANSES

    Glyoxylic acid replaces formaldehyde previously used in hair straightening, as the latter is considered dangerous for health due to its classification as “proven carcinogenic substance in humans”according to the International Agency for Research on Cancer. But it seems that this substance would ultimately not be a safer alternative.

    Depending on the results of its expertise, ANSES could propose changes to the European rules governing the use of glyoxylic acid. For the doctors who reported the clinical case, “cosmetic products containing glyoxylic acid should no longer be used”.

    An opinion shared by the General Directorate for Competition, Consumption and Fraud Repression (DGCCRF) and the General Directorate for Health (DGS) advises against using the product. “It is important to inform affected patients of the potential risks associated with the use of straightening products containing glyoxylic acid and to encourage them to consult a healthcare professional immediately if they experience any suspicious symptoms after using these products. ” writes Grégory Emery in a DGS note intended for health professionals, to alert them.

    It also invites them to report cases potentially encountered in their practice, within the framework of cosmetovigilance.

    The Federation of Beauty Businesses reacts to this announcement

    For its part, the Federation of Beauty Companies (FEBEA), believes that the conclusions drawn on glyoxylic acid should not be too hasty. “It is necessary to exercise caution before directly attributing these adverse effects to the presence of glyoxylic acid in the products,” she wrote in a press release. She also recalls:

    • cases of “misuse of products, the crucial importance of following the instructions for use of straightening products, in particular application to a healthy scalp (without damage) and the importance of consulting a hairdressing professional trained to the application of these products”
    • that “users suffering from kidney problems should inform their hairdresser so that a more suitable alternative, such as keratin straightening, can be favored”.

    Before concluding that “As product safety is a top priority, companies continue to educate professionals and the public on the precautions to take to ensure safe use.”

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