26 Israeli women were hospitalized for visiting a hair salon

Ronit (fake name) started to suffer one day from stomach pains, shortness of breath and fatigue and went to the doctor for blood tests. However, she never imagined that within one day, she would need to be rushed to a hospital with severe kidney failure and undergo dialysis.

And she certainly didn't imagine that this would all be caused by having gotten her hair straightened the day before.

Just like Ronit, 26 women (one woman per month on average) in Israel have been hospitalized with severe kidney failure after having their hair straightened.

These include:

• A 13-year-old girl
• A woman in her 15th week of pregnancy
• A 42-year-old woman who was sent to the hospital for kidney failure twice due to hair straightening

Some of these women managed to seemingly recover spontaneously. However, others required dialysis treatment.

Some will say that there are thousands of women in Israel each year who get their hair straightened, and "only" 26 women developed kidney failure.

To that, I point out that kidney failure that requires dialysis is very serious and is life-threatening.

Patients will tell you they wouldn't wish their medical trauma on anyone. This is a price that no one should have to pay for a simple cosmetic process.

From hairdresser to dialysis

In the 2000s, reports first began to emerge of symptoms from hair straighteners containing formalin. This was mainly from hairstylists that were exposed to the smoke inhaled during the straightening. 

These symptoms manifested in eye irritation, respiratory issues, a rash on the face, shortness of breath and pulmonary edema.

But for over a decade in Israel and the rest of the world, formalin use hasn't been approved.

But while modern hair straightening procedures don't contain formalin, they do contain something else: Glyoxylic acid.

This acid gets absorbed through the scalp, rich in blood vessels. Once inside the bloodstream, the glyoxylic acid decomposes into oxalic acid and calcium oxalate, both of which reenter the bloodstream and eventually leave the body through the kidneys as part of the urine.

Now, this itself isn't abnormal and all humans undergo this process to some extent, and it usually isn't harmful. But when exposed to extremely high doses of glyoxylic acid, one can develop a case of oxalic acid poisoning, causing kidney failure.

In kidney biopsies on the women who suffered kidney failure after getting their hair straightened, calcium oxalate deposits were found in their kidney cells.

Dialysis was able to remove the toxins, helping them recover and reduce the damage.

In 2021, a three-year-old girl tried to drink a hair-straightening product. She only tasted it and didn't actually ingest any of it due to its bitter taste, but it did result in the girl absorbing a minimal amount in her mouth. The result was only severe kidney failure that required dialysis, and not death.

Following this incident, the Health Ministry banned all licenses for hair straightening products that contain glyoxylic acid and contain a PH below 4.

But another problem was that the information on hair straightening products' labels aren't always reliable or fully honest. Back in 2010, one product in Ohio was labeled without formalin but it actually contained 8.5% formalin. In 2022, one product in Israel claimed to have no formalin and just 2% glyoxylic acid, but in fact, it actually contained 3,082 ppm of formalin and 26.8% glyoxylic acid.

Only in Israel

It is interesting to note that, aside from two cases in Egypt, all cases of oxalic acid poisoning in the world come from Israel. 

Is the "Israeli" women's liver metabolism different from around the world? Is the gene that breaks down glyoxylic acid just a bit "lazy" in Israeli women? Is there a link between the calcium oxalate deposits and the prevalence of the genetic condition hyperoxaluria? Will it be possible to offer these patients medical treatment like what's given to type 3 hyperoxaluria patients?

These questions are still being researched and we won't know the answer for many years. Until then, we shouldn't let a single woman in Israel risk their health.

And besides, if you want to straighten your hair, there are other products on the market that are much safer, with no glyoxylic acid and with valid Health Ministry licenses.

Dr. Mittal Kidar is the director of pediatric nephrology at Wolfson Medical Center.