There are concerns regarding the role that propylparaben may play in the development of breast cancer.
Propylparaben belongs to a family of chemicals known as parabens, which are compounds of parahydroxybenzoic acid. The others are methyl-, ethyl- and butylparaben. While these compounds occur naturally — in some plants, for example — they are synthetically manufactured and used primarily as preservatives and antimicrobials in cosmetics, foods, and pharmaceuticals. Propylparaben is the most commonly used form. The compound has very low toxicity, but there is concern that it may have a role in the development of breast cancer, among other things.
properties and uses
Propylparaben is used in many cosmetics and can be found in lipsticks, foundations and eye shadows.
Cosmetics, pharmaceuticals and foods can deteriorate due to the action of bacteria and fungi if they do not contain a preservative or antimicrobial agent. Studies have shown that propylparaben is effective at low concentrations. It is particularly good at killing or preventing mold growth and works well across the entire acidity range which includes most products intended for external or internal use. This, combined with its apparent lack of toxicity to humans and other mammals, and its low manufacturing cost, has led to its widespread use in a variety of products.
Propylparaben is a common ingredient in deodorants.
The compound is widely used in the cosmetics industry and is considered safe at concentrations up to 25%. It has become the preservative of choice, especially for water-based cosmetics – such as moisturizers, shampoos, shower cleansers, conditioners and sunscreens. Lipsticks, foundations, masks and eye shadows can also contain it.
Some mascaras contain propylparaben.
In the pharmaceutical industry, propylparaben is a common preservative for certain medications. As a result, it can be absorbed by humans in a number of ways: injections, orally, or through suppositories. Since these uses involve the compound being taken internally, it is not typically found in concentrations greater than 1%. The same applies to its use in food.
effects on humans
Propylparaben is found in many types of makeup.
Tests for acute or chronic toxic effects indicated that propylparaben has low mammalian toxicity. It can be mildly irritating to the skin and allergic reactions have been reported, but it is not believed to directly cause any other harmful effects. It is easily absorbed into the system when taken orally, but it is quickly broken down and does not normally seem to accumulate in the body.
The main concern with this substance is that, like other parabens, it can mimic, to some extent, the action of the female hormone, estrogen. Although essential for female development, early exposure to the hormone has been linked to breast cancer, and estrogen-suppressing drugs are used to treat the disease. There appears to be no direct evidence linking parabens to cancer, but several studies have been conducted that have created fear in some consumers.
In one study, a group of British researchers tested tissue samples taken from women with cancerous breast tumors. The researchers found traces of parabens in the lumps of all 20 women. This made some people wonder if these chemicals caused cancer.
Other examples of concern include a September 2008 study of 20 girls ages 14 to 19. The girls used various cosmetic products every day – from moisturizers to deodorants and makeup. In that study, propylparaben was found in all girls.
It is possible that parabens also affect men. In a study of male rats fed these chemicals at various doses, testosterone production was found to decrease in proportion to dose. As of 2013, there was no clear evidence of any adverse effects of these substances on humans, and research into them is ongoing, but many people are taking a “better safe than sorry” approach and trying to avoid products containing these chemicals.
Since there is increased awareness of these compounds and concern about their possible effects, some cosmetics manufacturers, especially those of an organic nature, are looking for alternative ways to prevent their products from spoiling or to inhibit microbial growth. Some may simply settle for shorter shelf lives, while other manufacturers look to other preservatives. Until more information is available, the safest course may be to limit exposure to parabens.