Q: There are some chemicals that have been called endocrine disrupters. What is this all about and what is Dow doing to protect the public from these chemicals?
A: It has been suggested that certain industrial chemicals in the environment can mimic the action of natural hormones and thereby impact the normal activity of the endocrine system in man and wildlife. This debate has been ongoing since the early 1990s. The endocrine system regulates and controls various bodily functions, including reproduction and development. A disruption or modulation of this control might have adverse effects on these endpoints. Thus, the potential for either industrial chemicals or materials occurring naturally in the diet or drinking water to act as "endocrine modulators" or "endocrine disrupters" has received widespread scientific, regulatory and media attention. Most attention centers on "estrogen mimics" - chemicals that interact with the endocrine system in ways that resemble natural estrogen, the primary female sex hormone.
Preliminary results of studies describing endocrine disruption did not always hold up to scientific scrutiny. Many of the results could not be replicated by different scientists in different laboratories. In order to resolve these issues, scientists have been working to develop standardized and validated testing methods to identify and assess endocrine disrupting substances. These can then be used to evaluate many chemicals to assess their potential to act as endocrine disrupters.
A major effort within the Organization for Economic Cooperation and Development is directed towards internationally harmonized and validated screens and tests for hormone active chemicals. Dow has been supporting the development and validation of such screens and tests through participation in the chemical industry's Long Range Research Initiative (LRI). Until such time as validated methods are developed and accepted by the scientific community, Dow's position is that the regulation or restriction of substances should be based on sound scientific data generated by validated methods and not on reports of possible endocrine disrupting effects in exploratory studies that have not been replicated. In addition, substances that may alter endocrine function will often require risk management decisions based on other toxicological properties or hazards that may supersede any risk management decisions based solely on endocrine disruption.
Some of the chemicals currently being studied can be found in the environment, but they usually occur in very low concentrations. While there are some studies indicating that the endocrine systems of animals have been affected following exposures to large amounts of some chemicals, there is little reproducible evidence that small amounts of these chemicals can cause endocrine disruption or adverse effects. This, then, is the most controversial aspect of the endocrine disruption hypothesis; that is, exposure to low doses of chemicals (well below those that have previously shown no hazardous effect) are actually causing previously unrecognized toxicity. This proposition has been examined widely within the scientific and regulatory community and the weight of scientific evidence has failed to confirm the claim. However, there are still those suggesting it is prudent and precautionary to impose regulation and/or advocate marketplace deselection of those chemicals which have been implicated in the so-called "low dose" debate.
Dow is committed to developing and promoting credible science-based decisions on industrial chemicals, with the safe handling and use of chemicals determined by the scientific principles of risk assessment. At this time, there is no reason to believe that chemicals that have some endocrine activity can not be managed effectively and safely used based on this principle.
Additional Information:
- American Chemistry Council (http://www.americanchemistry.com/s_acc/sec_policyissues.asp?CID=318&DID=1144 )
- US EPA Endocrine Disrupter Screening Program (http://www.epa.gov/oscpmont/oscpendo/pubs/edspoverview/index.htm)
- Our Stolen Future (http://www.ourstolenfuture.org/)
- CEFIC, European Chemical Industry Council (http://www.cefic.be/Templates/shwStory.asp?NID=471&HID=321)
- Organization for Economic Cooperation and Development (OECD) Endocrine Disrupter Testing and Assessment (http://www.oecd.org/document/62/0,2340,en_2649_201185_2348606_1_1_1_1,00.html)
