Plastic Drinking Water Bottles
By Sharon Skipton, Extension Water Quality Educator
and Bruce Dvorak, Extension Engineering Specialist
Questions have been raised about the safety of drinking water from reusable plastic water bottles:
- What information is provided by the number on the plastic bottle?
- What is the risk from Bisphenol A (BPA), and which plastics contain BPA?
- Do Nalgene bottles contain BPA?
We will attempt to answer some of your questions in this article as they relate to the use of plastic drinking water bottles.
Plastic Coding- Is #7 Plastic A Concern?
The code on plastic items appears as a triangle containing a number from 1 to 7. The code was developed for recycling purposes. The questions being raised at this time center on plastics with the number 7. Numbers 1 through 6 indicate the type of plastic the container is made of. Number 7, on the other hand, was designed for "other" plastics, and is used for all plastics that do not fit into the number 1 through number 6 designation. The number 7 represents different types of plastics containing different chemicals. Therefore, one cannot categorically make a risk statement about all #7 plastic products.
BPA - Where is it found?
BPA is a chemical used in production of some plastic products, including some reusable water bottles and baby bottles. BPA does not fit plastic #1 through #6 designations. Therefore, products containing BPA will have a #7 designation. While all plastic bottles containing BPA will have a #7 designation, not all plastic bottles with a #7 designation contain BPA.
While this article focuses on drinking water bottles, it is important to note that BPA may be present in a variety of other products such as baby bottles, liners of food cans, compact discs, dental sealants, eyeglasses, and more.
BPA - Is it a health risk?
The National Toxicology Program (NTP) is an interagency program created to coordinate toxicology testing programs at the federal level, strengthen the science base in toxicology, provide information about potentially toxic chemicals, and more. The NTP released their "Draft NTP Brief On Bisphenol A [CAS NO. 80-05-7]" April 14, 2008. (http://cerhr.niehs.nih.gov/chemicals/bisphenol/bisphenol.html) The draft was distributed for the purpose of public comment and peer review. It was not intended to represent their final conclusions or policy.
The National Institute of Environmental Health Sciences (NIEHS) released a summary of the NTP Brief (Since You Asked - Bisphenol A) (http://www.niehs.nih.gov/news/media/questions/sya-bpa.cfm). Key points have been taken from that document and appear below. The five levels of concern used by NTP are, from highest to lowest:
- Serious Concern
- Some Concern
- Minimal Concern
- Negligible Concern
"The National Toxicology Program (NTP) concurs with the conclusion of the Center for the Evaluation of Risks to Human Reproduction (CERHR) Expert Panel on Bisphenol A that there is some concern for neural and behavioral effects in fetuses, infants, and children at current human exposures. The NTP also has some concern for bisphenol A exposure in these populations based on effects in the prostate gland, mammary gland, and in earlier age for puberty in females."
"The NTP has negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects, or reduced birth weight and growth in their offspring."
"The NTP concurs with the conclusion of the CERHR Expert Panel on Bisphenol A that there is negligible concern that exposure to bisphenol A causes reproductive effects in non-occupationally exposed adults and minimal concern for workers exposed to higher levels in occupational settings."
The NTP concluded that "Recognizing the lack of data on the effects of bisphenol A in humans and despite the limitations in the evidence for "low" dose effects in laboratory animals, the possibility that bisphenol A may impact human development cannot be dismissed. More research is needed."
Nalgene bottles - Are these the bottles to avoid?
Some, but not all reusable Nalgene water bottles contain BPA. Some Nalgene water bottles contain a designation other than #7, indicating they do not contain BPA. Other Nalgene bottles have a #7 designation, indicating they may contain BPA. The company that produces Nalgene water bottles distributed a press release in April, 2008 indicating they would eliminate containers containing BPA from their Outdoor line of plastic containers. The press release stated that new water bottles will be manufactured with a BPA-alternative.
Plastic baby bottles and sippy cups - Are they safe?
Like plastic drinking water bottles, some, but not all plastic baby bottles and sippy cups contain BPA. Heating beverages in plastics containing BPA (as is done with baby formula) has been shown to result in greater BPA exposure. Some stores have reported that they are pulling infant and toddler products containing BPA from shelves. Some manufacturers have reported that they currently do not use, or will soon stop using BPA in infant and toddler products. Check with specific stores and manufacturers for current updates.
The numbered code on plastic bottles was designed for recycling purposes. Some, but not all plastic water bottles marked with a #7 contain the chemical BPA. Current science suggests there is negligible concern for impact on adults, but some concern for impact on fetuses, infants, and children from typical use of containers containing BPA. Additional research is necessary to definitively answer health risk questions.
Concerned individuals can make immediate choices including not heating beverages in plastic water bottles containing BPA and avoiding baby bottles and sippy cups containing BPA.