The United States Food and Drug Administration or FDA lists the reasons why kohl, an ingredient in some eyeliners, is dangerous and therefore illegal.

First among these reasons is that is contains an unsafe color additive, making it an adulterated product. Kohl is also known as al-kahl, kajal and surma. According to the FDA, we must be watchful for products, especially eyeliners containing kohl because it is mainly made out of heavy metals like antimony and lead, which are poisonous for humans.

Studies have shown that majority of kohl samples contain significant levels of lead. One study shows that eighty-eight percent of the kohl-based preparations contained significant amounts of lead.

Meanwhile other samples of kohl preparations have tested positive for aluminium, carbon, titanium, calcium, magnesium, oxygen, silver, silicon and sulfur, making them unsuitable for use on the eyelids.

Kohl is especially dangerous when used on children. Children are very sensitive to the effects of kohl, which oftentimes leads to lead poisoning. Thus, the use of lead-based kohl is strongly discouraged.

Second, labels in kohl eyeliner and kohl products sometimes contain labels falsely claiming to be approved by the FDA when the use and importation of kohl is illegal. On the other hand, it must also be noted that not all eyeliners that say are labeled as "kohl" are actually made from this poisonous substance. Sometimes, kohl refers to the color or shade of the eyeliner, which is a very dark black.

Third, kohl is not declared in the list of ingredients of some eyeliners and kohl-containing products, as it is illegal.

The FDA and studies warn us that despite having been used during the ancient Egyptian times as an eyeliner, kohl is by no means safe and acceptable as an eyeliner ingredient.