I made a couple of containers for my garden out of pallets. I wanted to protect them from rain, so I stained them with an exterior waterproof seal.

But later I read someone mentioning to avoid using treated lumber for containers in which you would grow edibles. I'm wondering how unsafe it could actually be or is it just a minor thing?

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    Usual warning about treated wood regards Arsenic and Chromium Treated Wood: ecy.wa.gov/programs/hwtr/dangermat/… You should not find anything like that in your product, but without complete chemical listing it's not possible to say the stuff is completely safe. That said, I'd use it with little qualm. Commented Jan 14, 2016 at 19:16

3 Answers 3


If your concerned about how chemicals might leach into the soil over time you may want to take this to the chemistry stack exchange.

I'll just say that unless I'm talking to someone who truly understand the chemicals within the sealant, I would not accept their recommendation unless it was a warning. So, as in the game of knights and knaves you are bound to get the wrong answer, the only answer would be to defer to caution.

I don't know what might be in those pallets from the sealant but I can't imagine any of it is OK. As well, I would expect any chemical to diffuse into any surrounding matter. As that is what all compounds do. Look at as milk in your tea but slower because we're dealing with a solid and not a liquid.

IMO, don't even burn them. Get rid of them in the most responsible way and move onto another material for your project.


The concern is regarding pallets treated with methyl bromide. If you use pallets you should use heat treated pallets, marked HT. If you use anything not marked HT, then you should line the inside with thick plastic.

The stain you used doesn't mention the chemical makeup, but it is designed to be water resistant and probably uses a silicon polymer, and is not supposed to come off on contact with a moist substance. It's probably safe but without knowing the exact chemicals used, you're probably be happier lining it with plastic.


I agree with Graham Chiu about methyl bromide. According to Toxipedia, Methyl Bromide is used as a pesticide to control pest insects, nematodes, weeds, pathogens, and rodents. In the U.S., methyl bromide has been used in agriculture, primarily for soil fumigation, as well as for commodity and quarantine treatment, and structural fumigation.

It can enter your body through inhalation by air contaminated with methyl bromide.

The symptoms of inhalation of methyl bromide are abdominal pain, convulsions, dizziness, hallucinations, headache, vomiting, weakness, loss of speech and in-coordination.

But, ever since 2005, methyl bromide has not been used to fumigate pallets. There are many more things you need to consider before trying these techniques. Getting a help from landscaper would be an added advantage for you. For more info on this go here.

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