Studying exposure to hair dyes from decades ago may not be the same as studying current exposures. Early hair dyes contained chemicals, including some aromatic amines, which were found in the late 1970s to cause cancer in lab animals, so hair dye manufacturers changed some of the chemicals in their products. On top of this, the ingredients in hair dyes have changed over the years. Studying something like hair dyes can be even more complex because not all hair dyes are the same – they can contain any of thousands of different chemicals. In most cases neither type of study provides enough evidence on its own, so researchers usually look at both human and lab-based studies when trying to figure out if something might cause cancer. But sometimes it can be hard to know what the results of these studies mean, because it is hard to account for the many other factors that might affect the results. Such a study might compare the cancer rate in a group exposed to a substance to the rate in a group not exposed to it, or compare it to what the expected cancer rate would be in the general population. Still, it’s not always clear if the results in lab dishes or animals would be the same in humans, for a number of reasons.Īnother type of study looks at cancer rates in different groups of people.
In lab studies, researchers can control many of the other factors that might affect the results. Researchers may also expose normal cells in a lab dish to the substance to see if it causes the types of changes that are seen in cancer cells. In studies done in the lab, animals are exposed to a substance (often in very large doses) to see if it causes tumors or other health problems. A substance that causes cancer or helps cancer grow is called a carcinogen. Researchers use 2 main types of studies to try to figure out if a substance causes cancer. Some studies have suggested possible links, but others have not. Studies have looked most closely at the risks of blood cancers (leukemias and lymphomas) and bladder cancer. Researchers have been studying a possible link between hair dye use and cancer for many years. Many of the concerns about hair dyes possibly causing cancer have focused on people who work with them. People who work around hair dyes regularly as part of their jobs, such as hairdressers, stylists, and barbers, are likely to be exposed more than people who just dye their hair on occasion.
#Removing ammonia from hair color machine skin#
Some chemicals in hair dyes can be absorbed in small amounts through the skin or inhaled from fumes in the air. The most common way to be exposed is to dye your hair or have it dyed. Because darker dyes have more of some chemicals that may cause cancer, these products are of greatest potential concern. Darker hair dyes tend to use more of these coloring agents.Ĭoncern about cancer risk is largely limited to the semi-permanent and permanent dyes. In the presence of hydrogen peroxide, these substances go through chemical reactions to become dyes. They contain colorless substances such as aromatic amines and phenols. These dyes are sometimes referred to as coal-tar dyes because of some of the ingredients in them.
They are the most popular types of hair dyes, because the color changes last until the hair is replaced by new growth. Permanent (oxidative) hair dyes: These dyes cause lasting chemical changes in the hair shaft.They typically last for 5 to 10 washings. Semi-permanent dyes: These dyes do penetrate into the hair shaft.Temporary dyes: These dyes cover the surface of the hair but don’t penetrate into the hair shaft.People are exposed to the chemicals in hair dyes through skin contact. Hair dyes vary greatly in their chemical make-up. Here is what the research shows so that you can make choices that are comfortable for you. Many studies have looked at hair dyes as a possible risk factor for various types of cancer. You may have heard rumors about a link between using hair dye and getting cancer. Many American women, as well as a small but increasing number of men, use hair dyes.
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