Arsenic

[RCBill 14]

Howdy,

I was talking to a counter guy today about TWP and Wolmans. He mentioned that contractors were having trouble with the arsenic in new wood. I don't recall anything being posted here.

Does anyone have information on this subject?

Ken W., no email anywhere. Look forward to meeting you.

Bill

[JBenson 14]

Somebody correct me if I am wrong, but as far as i know arsnic is no longer used as a wood preservative, it has been 5-6 years since they have used it. Now they use some copper based stuff for sealing i think.

[RCBill 14]

Yep, I mixed it up. We were talking about copper.

[RPetry 564]

Bill,

You can do a Goggle search on CCA and ACQ woods. These are chemical compounds that the lumber industry has used over the years in pressure treating wood.

The industry voluntarily stopped using CCA for pressure treating at the end of 2003 if I recall, due to complaints about arsenic in the product.

Alkaline copper quaternary (ACQ) and copper azole (CA) chemical compounds are now being used.

I have applied Ready Seal to ACQ pressure treated wood and have had no problems in stain penetration, color shift, or stain longetivity.

[PressurePros 249]

It's extremely green. I am off to do a deck today that has a small addition built onto it. I treated it with heavy duty stripper and a ton of acid when I cleaned it so I hope there is a little better balance.

[Beth n Rod 1,279]

Arsenic is no longer added to wood as I understand it. A couple years back, the govt. banned new construction with CCA treated lumber. The new pressure treatments out there that we see most often are CA-B and ACQ. Copper seems to be the new common ingredient and it has issues all its own. The types of fasteners and such that used to be used in construction have changed, due to the corrosive nature of the new chemical treatment. It is still advisable to have a deck sealed to help make sure to cut down on the leaching out of the chemicals and the amount of human exposure. There are not new studies at this time outlining the effects of the new chemical treatments....give it 10 years, and there may be....

Beth

[Beth n Rod 1,279]

http://www.chemspec.com/products/preserve/

[Beth n Rod 1,279]

Copper is the ingredient that is most prominent in pressure treated wood today. With the EPA ban on CCA wood there is no longer any in production as of 12-31-2003.

New wood containing either CA-Copper Azole is widely used in our area or ACQ-Alkaline Copper Quaternary (quat for short). What we have been seeing in the CA wood is veins of copper exuding from the wood and hardening on the surface which looks a pale green same as the patina you see on statues. ACQ wood can tend to be a bit difficult to get a stain to penetrate. Washing beforehand helps but does not aleviate the problem.

Rod!~