Thanks for the information. As far as testing the wood goes, is there something simple I can pick up from Home Depot or something?

I don't know of a way to test wood for these substances.
I would try searching thru science experiments online
that deal with litmus tests and testing for metal content.

I really doubt you have anything to worry about.
Lumber treated with CCA has been off the market for a while now.
Now ACQ is used in the treatment process, and is safe.
The wood has a pH above 7 making it alkaline so bugs won't bother it.
And the copper quantenary molecules protect it from rot.
There is also MCQ, which is the same as ACQ, except the CQ
molecules are much smaller so more of them can infiltrate
the wood fibers. MCQ = (alkaline) Micro Copper Quantenary.

I would be very supprised if you had a pallet made of treated wood.
Especially treated with CCA (copper chromate arsenic).
CCA was banned sometime around year 2000.

Found this with a Google search:
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http://lumberjocks.com/topics/2605
The other method.......was patented by the University of Miami. It is a orange-colored chemical that you can spray on the wood with a spray bottle that will turn bright red in the presence of chromium, which is always present in CCA wood. The product is called PAN Indicator Stain, and was developed in 2003.

Last time I checked it was available from SPECTRUM (800-772-8786). The part number is P-358 and used to cost $21.90 + shipping. Please be sure to read the MSDS on this chemical  as it has to be handled carefully, as I recall. But, it works well, and I have a small amount on hand and have used it myself to identify CCA wood on my property.

ItÂs easy to use, too. You find an unpainted portion of the wood and spray it on. (Painted wood can test positive, due to trace metals in some paints, so use it only on unpainted wood.) After spraying, wait 2-3 minutes. If the color changes from orange to red or a darker color  it contains chromium metal and should be disposed of properly (and never burned  which will release the arsenic in the CCA).
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You may could test for copper content by testing electrical
resistance in a sample of wood with a known moisture content.
Electrolosis is used for other substances, mite work for wood.
Swimming pool test kit that tests for copper might could work.
Burning a sample of the wood in a neutral flame would work.
If the flame turns green then the wood contains copper.
These are just brainstormed ideas. No guarantees about any of them.
(Disclaimer)

I'd be interested to know if you find out anything.
Myself, planters have been built for many years using treated
wood. Even with CCA treated wood. I wouldn't worry about it.
Or if I had to worry about it, I would line the planters with plastic.

Pooh Bear

Thanks for all that detail.

I noticed that the pallets I had were stamped with "HT" and some according to Wikipedia that means that they've been heat treated, which I assume is fine in that no chemicals were used.

Just a guess, but heating them would remove most of the moisture.
That would help keep the weight down, decreasing shipping cost.
I have noticed that new pallets are extremely dry.
I'd have to look into this more tho.

Pooh Bear

As a rule, treated wood commonly sold to the public is pine. The treatment recipe turns the wood a bit more green than normal(CCA) and a lot mopre green(ACQ) than normal. The other treatments actually look like the wood has been painted green.

If the wood has aged to a gray color on the exterior, making a fresh cut to expose the interior will show the color. Yellow/white means no treatment.

PT wood is treated so the effects of time/insects/water do not have as much effect---the wood lasts much longer than untreated wood.

There are two basic kinds of pallets---heavy duty and one use. One use pallets are often made of pine. They are used for shipping appliances and small machinery. The wood is thin and can be torn apart easily. Heavy duty pallets are built for repeated use and sometimes have to be cut apart, as the glue/fasteners make tearing them apart very difficult. These types are usually made of white oak. I have never seen white oak treated with the same stuff that is used for pine.

Why not just get some cedar or cypress and build you planters out of wood you KNOW hasn't been treated. Most pallets aren't built out of wood suitable for this kind of project anyway. Save the pallets for flower planters or some other project.

Hi I have the same question. I have a piece of found wood labeled:

TECO
TESTED EXPOSURE I
SGEATHING SPAN
40/20
19/32"
HUD UM 40C
PRP 133
MILL 164

Also it says GRAVEYARD on it.

The wood does not look green, and I cut a piece off to check, and it is not green on the cut either. But, since I plan to use this in my garden I want to know for sure if it is safe to use. Does anyone know what this label and numbers mean?

Thanks

it's 5/8" sheathing and from that I would have no way to tell for certain but I doubt very much that it was pressure treated.

Your wood is not treated. According to Teco website your wood was designed for indoor construction.

Here is the link i found my information.

Here is a link that might be useful: Teco explaination of markings

I agree with Mike. Why not get the best wood for your food project. Then you will also know it's food safe.

I was also wondering about the safety of pallets. I know it a few years later but I found several sites and I will attach one. http://www.treehugger.com/sustainable-product-design/how-to-tell-if-your-pallet-is-safe-to-reuse-pallet-safety-info.html

I bought and stained what was marked :P/T Wood at Lowes. It was yellowish/white. I kept saying it was NOT P/T lattice. (even tho the tag on it said "P/T") It soaked up the stain like crazy. Is there anyway I can do some test to see if it is P/T or not?

If it has a tag attached to it and the other pieces of the same lattice also had tags, it's pretty reasonable to assume that it is pressure treated. When wood is "pressure treated" it's put in a large tank, the tank is filled with a solution of chemicals and then pressurized which forces the solution in to the wood. That's why pressure treated lumber often has such a high moisture content. With something like thin lattice, it's going to dry back out pretty quickly. It's also possible that the components of the lattice are treated before assembly, which may give the wood even more time to dry. It's quite possible for it to really soak up stain, especially if the lattice has been sitting around for a while.

I suppose you could send a piece off to a lab for analysis but I don't know of a way to test at home.

OK I know this is reAlly old but if anyone is still reading is this treated wood? The green comes up if you scratch at it

I'm late on this too, generally confused about how to figure out treated vs. not. Is plain old wood sold from home depot treated? Like the long 2x4s for random projects? As for the above photos, of what little I do know, I would think so, yes @Devin- deck wood is often treated wood because of the non-stop exposure and its need to remain stable while holding you + grill + doggo 5+ feet above ground.

Home depot and other big box stores will sell 2x4 lumber in both treated and non. Treated lumber generally will be marked but also have a greenish tint to it.