"Old" Pressure Treated CCA Lumber Isn't Safe Either

Many people are under the misconception that using "old" (an ambiguous age determination) CCA (Chromium Copper Arsenic) pressure treated lumber in a building project that would (a) come in contact with children and pets; or (b) come in contact with edibles, as in construction of a vegetable-garden bed enclosure; or (c) a compost pile is acceptable because they think the arsenic has either leached out of the lumber after a point or by placing it a pre-determined distance from edibles, the arsenic won't affect growing vegetables.

Wrong.

There are numerous sources of information out there on the Internet for people to research if exposing their families and themselves to inordinate measures of inorganic arsenic is important to them. Inorganic arsenic is synthesized as opposed to naturally-occurring organic arsenic found in water, soils, etc. This information sheet about CCA lumber also includes the EPA's "acceptable" limits of arsenic exposure. ( I usually take those EPA recommendations and halve them.)

Sadly, too many people are either too lazy or find it confusingly mind-boggling to type a few words in a dialog box on a search engine, like Google, and hit "Search". I fully admit I was more than a bit befuddled by this thing with the blinking cursor but I soon realized one didn't have to become a computer nerd to type and hit a key. I digress.

"Old" pressure treated lumber is perhaps as deadly or at least unfriendly as "new" pressure treated lumber. Thankfully, as of a few years ago, there is no longer any "new" pressure treated or CCA lumber being produced because the EPA in it's infinite wisdom(?) finally outlawed it, recognizing its arsenic-leaching potential as hazardous to health. Studies (again, look them up) have found that once the lumber begins to break down, the pressurizing which encapsulated the arsenic becomes compromised, thus releasing all that was soaked into the lumber....into the soil and more easily onto unsuspecting little hands and paws.

An excellent paper on this is from Dr. Linda Chalker Scott of Washington University, which you can read here.

When dealing with these "old" timbers people are also of the mindset that if they dispose of them (please, please do not burn these carcinogenic creations) that they will wind up in a landfill and spread their poisons there. This is quite true. Therein lies the conundrum of what to do with the stuff. Having been in that same place and faced the same predicament, I found other uses for them which were as out of harm's way as possible and certainly no where near my vegetable garden. One can be creative. After all, that's one of the finer points of being an organic gardener: working out safer methods to otherwise hazardous problems.