Most tampons are made of cotton and may include a synthetic fiber, viscose rayon, to improve absorbency. The cotton used in conventional tampons is not organic and therefore, heavily doused with pesticides and insecticides while grown. Cotton is one of the most heavily sprayed crops grown in the US. Many chemicals used on cotton crops are not safe for use on food crops. Finished tampons can contain traces of the chemicals used on the cotton crop.
The conventionally-grown cotton is then bleached for fiber uniformity and to improve absorbency. Although chlorine gas is no longer used to bleach tampons, chlorine dioxide - a chlorine derivative - is commonly used. Traces of dioxins, a group of toxic chemical compounds created by the chlorine bleaching process, have been found in conventional tampons. Dioxins accumulate in our bodies and build up over time. They have been shown to cause cancer and other health problems.
Viscose rayon is one of several absorbent synthetic materials introduced to tampons in the late 1970's. Increased cases of Toxic Shock Syndrome (TSS) was linked to these synthetic ingredients. Researchers found that synthetic fibers could increase the toxins that cause TSS. The use of the most harmful of the synthetic tampon ingredients has been discontinued, but viscose rayon is still commonly used today.
The process of making rayon fibers, which includes the use of wood pulp, also produces dioxins. Traces of dioxins can also be found on rayon fibers used in tampons.
