The first was a rumor I heard in the late nineties and only recently asked Seth, my chemistry guru, about. What I heard was something along the lines of, "I don't use mainstream tampons anymore because they bleach them and they get contaminated with dioxin." Of course, I had no idea what dioxin was, but I also don't use tampons (I'm weird that way), so I didn't really think about it again until...
The second was information that I came across online that stated there are several "toxic" ingredients being used in the cosmetics industry. The information seemed to be presented in a pretty reasonable way and I'm no chemist, but I tried just doing a general search online and came up with all kinds of things being used in cosmetics that various people were claiming to be toxic. My thought was, "Why are they allowed to put all this stuff into cosmetics?!"
Instead of letting the panic continue, I called Seth and and gave him the skinny. He felt it was an interesting thing to research. Since I had just remembered the tampon/dioxin rumor, we started there. So, in case you were worried, we do realize that tampons aren't cosmetic. And away we go:
Jess: So...what the heck is dioxin?
Seth: Dioxin is the common name for the chemical compound 2,3,7,8 tetrachloro-dibenzo-dioxin...
Jess: What the what?
Seth: TCDD for short, it is a highly potent carcinogen. It disrupts the ability of the body's defense system to target and kill cancer cells.
The plural term "dioxins" is used to refer to a group of seventeen "dioxin-like" compounds, which share the basic structure of TCDD. But the toxicity of these compounds is between 10-1000 times lower than that of the highly toxic TCDD. Both TCDD and these dioxin-like compounds (from here on out, we'll refer to them as just "dioxins") are monitored in the environment and regulated by the EPA (Environmental Protection Agency).
Jess: So there are eighteen of these compounds (including TCDD) out there - how did they get out there in the first place?
Seth: Traces of TCDD and dioxins are found in the air, soil, waste, water and food, but they aren't produced for any commercial purpose. They are by-products of certain industrial processes. For example, the bleaching of wood pulp with chlorine gas, the synthesis of certain herbicides, and the burning of hazardous waste.
Herbicides, whose synthesis produced TCDD and dioxins, such as those in Agent Orange, have been banned since 1985 by the EPA. Non-chlorine bleaching of wood pulp has been phased in by manufacturers to eliminate that source. Burning of waste remains as the major source of this contamination. But food is the major source of human exposure to these compounds, which accumulate in the fatty tissue of animals. The EPA regulates the level of these compounds in drinking water and the FDA (Food and Drug Administration) regulates the levels in food (1). The EPA's long-term goal is to completely eliminate environmental TCDD and dioxins.
Jess: ...Have we gotten to the tampons yet?
Seth: Almost there. In 1989, reports began to circulate in the media, alleging that tampons contained toxic amounts of TCDD and dioxins. This suspicion appeared possible, since the rayon fabric in some tampons was made from wood pulp and it was known that bleaching wood pulp with chlorine gas could produce trace levels of both TCDD and dioxins (as by-products).
These allegations caused great concern, coming so soon after: The implication of dioxin exposure as the cause of a variety of toxic symptoms (cancer, birth defects, immune system suppression) experienced by Vietnam veterans who were exposed to the use of Agent Orange defoliant. And an increase in incidents of TSS (toxic shock syndrome), attributed to bacterial contamination of tampons (2).
Jess: So some amount of TCDD and/or dioxins was found in tampons, but how much of it?
Seth: In 1989, the EPA estimated a lifetime daily dose of TCDD/dioxin due to rayon tampon usage was equivalent to one trillionth of a gram of dioxin, accumulated over 80 years. This was approximately one million times lower than the EPA's estimated dioxin dose due to food intake.
Just the same, by 2000 (and some before then), tampon manufacturers had switched from chlorine gas bleaching of wood pulp to either bleaching with chlorine dioxide, or to totally chlorine-free bleaching. Fibers made from wood pulp bleached with chlorine dioxide did not produce any detectable TCDD or dioxins using analysis methods which were sensitive to four-hundredths of a part per trillion.
Jess: In other words...their equipment couldn't detect any.
Seth: Precisely. Now, despite the aforementioned EPA estimates and the switch away from chlorine gas bleaching, popular concern about tampons and TCDD/dioxins remained sufficient so that in 1997 Congress passed the Tampon Safety and Research Act to ensure that tampon materials did not contain these contaminants. The FDA would henceforth stipulate that manufacturer submissions for tampon product approval should document testing of both tampon materials and finished tampons for TCDD and dioxins, as well as identifying the bleaching method used on wood pulp as either elemental chlorine free or totally chlorine free (3).
In 2002, EPA scientists reported that they were able to barely detect several dioxins in rayon tampons at their method's detection limit of approximately one tenth of a part per trillion. TCDD itself and most of the seventeen regulated dioxins could not be detected and thus were present, if at all, at levels below one tenth of a part per trillion (4). In 2005, FDA scientists confirmed the 2002 EPA findings, using a method with a detection limit down to four hundredths of a part per trillion (5). The FDA paper re-emphasized the fact, as have several FDA bulletins, that exposure to TCDD and dioxins in food dwarfs the exposure through tampon usage.
Jess: So can we conclude that bleached tampons nowadays are not hazardous to our health due to TCDD or dioxins? Or is there still some reason to only use chlorine-free/unbleached tampons?
Seth: Today the bleaching process for tampon fabrics in the United States should be either elemental chlorine (chlorine gas)-free or totally chlorine-free. Potential levels of TCDD or dioxins in these tampons should be either zero or so low as to not have a significant impact on health.
In conclusion, those who want to reduce their exposure to dioxins should consider reducing their intake of meat and fish rather than discontinuing their use of bleached tampons. It should be noted that the early concerns over the tampon issue and the 1997 congressional action accelerated the switch away from chlorine gas bleaching of wood pulp, a significant benefit to the environment.
(1) EPA Fact Sheet - Dioxins and Furans
(2a) R. Sciallo, Reproductive Toxicology, 15, 231 (2001) - Tampons, Dioxins and Endometriosis; (2b) 2009 FDA Bulletin on medical device safety - Dioxin and Rayon Concerns; (2c) 2009 FDA Bulletin - Tampons and Asbestos, Dioxin and Toxic Shock Syndrome
(3) FDA Recommendations for Submissions for Approval of Menstrual Products - 2005
(4) M. deVito and A. Schechter, Environmental Healthy Perspectives, 110(1), 23 (2005) - Dioxin and Furan Levels found in Tampons