Rain Barrels, Part 2: Barrel Materials
If you missed Part 1 of this two-part series, click here to learn some simple strategies to significantly reduce the synthetic chemical load of your rain barrel water--regardless of what material your barrel or roof is made of.
I must start by saying that if you already have a rain barrel, made of any material--wonderful! This article is intended to assist individuals who haven't made the purchase yet and are looking for pointers. It's not intended to freak you out about what you already have. I have no plans to dispose of our non-potable-water barrel to get a new one, and I'm not encouraging you to do so, either. (Our intention in using rain barrels is to reduce waste, right?) The simple strategies offered at the link above can make a big difference in improving your water quality, and that's where we're focusing our energy in our garden.
Stainless Steel Barrels
Rain barrel materials carry the same pros and cons as water bottles folks carry for drinking. If you have access to a stainless steel vessel, they have a long life and resist breaking down over time. This is why stainless steel water bottles and cookware have grown in popularity compared to their plastic and aluminum counterparts. In the long run, paying $500 for a 100-gallon stainless steel barrel that will last a lifetime is a great investment if it's feasible. And, my--isn't this a handsome barrel?
Plastic Barrels: Food-Grade vs. Non-
Realistically, many folks will be using plastic rain barrels. They are easier to find, lightweight, and typically more affordable than stainless steel. Plastic rain barrels are typically made out of polyethylene plastic (ATA). Just like plastic water bottles, plastic rain barrels leach some quantity of endocrine-disruptors and other toxins into the water it holds.
In addition to the strategies outlined in part 1, one variable that may cut down on chemical leaching is to use containers intended for rainwater catchment--specifically barrels that are safe for potable water. One difference between plastics intended for drinking water is that they are not treated with UV inhibitors. These are synthetic chemicals intended to maintain the integrity of the plastic longer in the presence of sunlight--but the FDA has deemed them unsafe for containers used for drinking (ATA).
Non-Food Safe Barrels
For the sake of folks (like me) who aren't sure what kind of barrel they have, I messaged Curbell Plastics to ask what types of chemicals are used as UV inhibitors in outdoor plastics. Erin in Customer Service kindly got back to me, letting me know that the manufacturer wouldn't release that "proprietary" information.
I assume the FDA knows that contaminants from the plastic itself are leaching out faster without the UV inhibitors--which is also undesirable. If the FDA considers that to be safer than adding UV inhibitors to the water, I will assume that UV inhibitors are worth avoiding if we have the option.
I did an internet search to see if I could find a rain barrel that looked similar to what we use. I found this product on Uline's website:
Source: www.uline.com
Though it contains "FDA compliant resins," that doesn't mean they're safe for drinking water. In the Additional Info section, the company states that this product "Does not carry FDA or NSF approved certification required for storing drinking water."
The Additional Info section also states that the barrel is bisphenol A (BPA) free--implying that safer chemicals were chosen. BPA has been found to cause a number of health issues, and its endocrine disruption mechanism shows its face at the tracest of amounts (Acconcia). However, companies generally use a chemical very similar to BPA in its place, such as bisphenol S (BPS)--a chemical that also appears to be unsafe, but hasn't garnered enough research to be pulled off the market (Service).
In the United States, we do not have a precautionary principle guiding our chemical regulations. Chemicals do not need to be proven safe before being widely used. The burden of proving a product is harmful--and the responsibility to avoid that product--falls on the consumer and society at large (Mackendrick, 20). When overwhelming evidence is finally available to justify banning a chemical like BPA, companies can move on to using a closely related cousin until enough evidence exists to ban it, too--if that evidence ever arrives (Williams). All this to say--we shouldn't be lulled into trusting a product simply because it is "free" of one particular toxin.
Food-Grade vs. Food-Safe Plastic Barrels
Though most of us aren't sticking our faces in these barrels and quenching our thirst, I certainly like the idea of watering my vegetable and herb garden from a container that is as toxin-free as possible. "Food-safe" or "Food-grade" barrels are the way to go with this intention. What's the difference between these two designations?
According to the Rainsaucers Stand Alone Rainwater Harvesting Company,
Food safe is OK for a wide variety of kitchen uses but not necessarily for long term storage. That is where food grade comes in. The FDA reserves food grade for food packaging and is designed to ensure the long term safety of the food in the container. The idea is to prevent leaching: food grade plastic does not contain any dyes or recycled plastic deemed harmful to humans. In addition, the food grade designation means no other harmful chemicals were used in either the resin or in production of the plastic container.... [O]ur catchment system is made of 100% virgin, no-dye HDPE- meaning its highly food safe and ideal for catching water and relaying it to a barrel or bucket. The key then is to make sure that any barrel being used in conjunction with our system for drinking water should be food grade and say so on the container.
To say that any plastic material contains "no harmful chemicals" is inherently false, as far as I understand. However, it certainly seems advantageous to select a barrel that is designated food-safe or food-grade by the FDA.
If you go to a farm supply store like Tractor Supply Company, you will find a product like this:
Source: www.tractorsupply.com/
In addition to being objectively cuter than the blue barrel, Tractor Supply says:
"We use BPA-free FDA-approved polyethylene plastic. It is cleared by the FDA specifically for contact with edibles."
We now know that BPA-free means nothing of substance. However, its safety for contact with edibles catches the eye. I messaged Tractor Supply Company which designation this barrel was given, and will update the article when I find out. Wherever you shop for a rain barrel, this might be an interesting question to ask.
One company that caught my eye was the Great American Rain Barrel. Their barrels are repurposed food shipping containers, and thus claim to be "food-grade."
Whatever barrel you find yourself using, three cheers for water conservation and serving your plants the water they most enjoy! Stay tuned for the next article, where I'll back up and discuss why rainwater is the bee's knees as far as your plants and pollinators go.
Sources:
Acconcia, Filippo, Valentina Pallottini, and Maria Marino. "Molecular Mechanisms of Action of BPA." Dose Response, 13(4). Oct-Dec 2015. www.ncbi.nlm.nih.gov/pmc/articles/PMC4679188/
Alternative Technology Association (ATA). "Water Self-sufficiency A Rainwater Tank Buyers Guide." ReNew: Technology for a Sustainable Future, no. 145 (2018): 57-67. Accessed January 19, 2020. doi:10.2307/90025497.
Center for Rainwater Harvesting. "Roof and Gutters: Safe Materials." 2006. http://www.thecenterforrainwaterharvesting.org/2_roof_gutters2.htm
Service, Robert F. "BPA substitutes may be just as bad as the popular consumer plastic." Science Magazine, Sep. 13, 2018. https://www.sciencemag.org/news/2018/09/bpa-substitutes-may-be-just-bad-popular-consumer-plastic
Williams, Florence. Breasts: A Natural and Unnatural History. 2012.
