Creosote-treated timbers: Cut with care

Some wise precuations to take if milling lumber previously treated with creosote. September 21, 2000

I have someone who wants me to cut a bunch of treated timbers (6-inch by 16-inch creosote-covered fir) into 2-by-4 and 2-by-6 stuff. The timbers look like railroad ties on steroids.

Is there anything I should know before running my bandmill through this stuff?

First of all, if properly treated, these timbers won't have creosote just on the outside, but will have penetration into the wood. If these are Douglas fir they won't have really deep pentration, since Doug fir is very hard to treat.
When cutting these, you will want to wear long sleeves and long pants, and preferably some type of hood, like a sandblaster would wear, for really good protection. At a minimum, wear a dust mask or respirator and a full-face shield with safety goggles underneath. Also, try to do your sawing in the shade if at all possible. If you have really fair skin or are not used to being around creosote you may wind up with a mother of a sunburn.

One last note: Be prepared to go through a bunch of blades if you have a lot of cutting to do. If these timbers were treated with "creosote-coal tar solution" as opposed to "coal tar creosote," they will have lots of solids -- technically "matter insoluble in xylene."

Lots of older stuff, especially, was treated with CCTS instead of CTC.

The end grain of Douglas fir treats well. Also, coastal DF treats deeper than inland DF. It is common to have DF incised (small cuts made into the wood) to enhance penetration. So it is possible to get substantial penetration.
The warnings from the last poster on the hazards are good. But what about disposal of the sawdust? Check with the local people to make sure you can get rid of it. Burning is not an option unless you can get a real hot fire. The pollution concern may make it impossible to help this person.
Gene Wengert, forum moderator

Here's some info on creosote pressure-treated wood from consumer information sheets:
This wood has been preserved by pressure-treatment with an EPA-registered pesticide containing creosote to protect it from insect attack and decay. Wood treated with creosote should be used only where such protection is important.

Creosote penetrates deeply into and remains in the pressure-treated wood for a long time. Exposure to creosote may present certain hazards. Therefore, the following precautions should be taken in handling the treated wood.

Handling Precautions
Dispose of treated wood by ordinary trash collection or burial. Treated wood should not be burned in open fires or in stoves, fireplaces, or residential boilers because toxic chemicals may be produced as part of the smoke and ashes. Treated wood from commercial or industrial use (e.g., construction sites) may be burned only in commercial or industrial incinerators or boilers in accordance with state and Federal regulations.

Avoid frequent or prolonged inhalation of sawdust from treated wood. When sawing and machining treated wood, wear a dust mask. Whenever possible, these operations should be performed outdoors to avoid indoor accumulations of airborne sawdust from treated wood.

Avoid frequent or prolonged skin contact with creosote-treated wood; when handling the treated wood, wear long-sleeved shirts and long pants and use gloves impervious to the chemicals (for example, gloves that are vinyl coated).

When power-sawing and machining, wear goggles to protect eyes from flying particles.

After working with the wood, and before eating, drinking, and the use of tobacco products, wash exposed areas thoroughly.

If oily preservatives or sawdust accumulate on clothes, launder before reuse. Wash work clothes separately from other household clothing.

Coal tar pitch and coal tar pitch emulsion are effective sealers for creosote-treated wood-block flooring. Urethane, epoxy, and shellac are acceptable sealers for all creosote-treated wood.

A month ago I had a similar request to split a couple of 8-by-14-inch by 28-foot railroad bridge beams to make pole barn posts. I really didn't want to do it but it was a good customer so I finally agreed. When they showed up with the beams, they had about 20 of them. 10 they wanted split down the middle as first requested and another 10 beams, 8 to 12 feet long, they wanted 2-by-8s out of.
We picked a cool morning with a breeze and had our mill set up outside. We used most all the precautions previously described. I would start the saw and then step back until it got to the end and then step back in to stop the saw head. We would wait until the dust cleared before removing the beam and replacing it with another.

The wood must not have been Douglas fir; it was very soft. I started with a used blade because I expected to hit metal or rocks but I didn't, and completed the job quite well with the one blade. The beams had very little tar buildup on the outside but the penetration looked very deep.

We returned all the scraps to the customer. The sawdust was mixed with a considerable volume of oak sawdust and spread across the log lot.

After sawing, we all took a shower and put on fresh clothes. Having purposely chosen to wear worn-out overalls and an old shirt, I disposed of my outside clothes.

That evening my face, neck and arms itched like the latter stages of sunburn and I had a headache. It may not have been related, but that night I developed some intestinal problems that lasted for three days. I had the most contact with the sawing. The others involved didn't complain of symptoms.

Soon after sawing, we called the customer to come and get the re-sawn beams, as they really smelled bad after being sawn. He came that evening and picked them up. Unfortunately, they were back before dark with two more to split and two more to make 2-by-8s out of. We agreed to saw these but no more.

We did resaw treated lumber once, never will again. We had also itchy skin and headaches.
A note about ecology - one of my basic principles is that we should try to borrow raw material from nature and return it in a way that it is in a state that nature could recycle as easy as possible. Many construction materials have appeared on the market that make us believe that we beat nature, like treated wood, vinyl siding, etc., but the problem of disposal is not addressed.

Some people react in different ways to exposure to creosote. Extreme symptoms of overexposure to creosote are headache, dizziness, difficulty breathing, stomach pain/cramps, etc. After all, creosote is a strong pesticide; that is why it works very well at preserving wood.
About the penetration: It could be that you sawed Southern yellow pine or ponderosa pine or another easily penetrated species instead of Doug fir. In my experience with SYP it is not uncommon to have 100 percent sapwood penetration, even though that is not a rule book requirement for proper treatment.

Treated wood saves trees. Think how many more trees would have to be harvested if everything that is built of treated timber had to be replaced every few years. Also, alternative materials such as steel, aluminum, and concrete consume up to 15 to 20 times more energy in the manufacturing process. That means 15 to 20 times more air pollution from coal burning or 15 to 20 times more radioactive waste from nuclear generation.

As far as disposal goes, the Consumer Info Sheet I posted explicitly states that appropriate disposal for creosote treated wood is by ordinary trash collection and disposal means. The CIS was approved by the U.S. Environmental Protection Agency, and I can guarantee you that the EPA didn't cut some back door deal with the industry because they would like nothing more than to see creosote treating plants put out of business.

I don't know about saving trees - we can grow them. At least we do!
I do know that exposing ourselves and employees to unreasonable health risks is foolish. We refuse to saw, resaw or machine any treated material because of this, and because fuel residue markets require us to sign an affidavit that our fuel residue contains nothing but wood fiber. Preservative-treated forest products(considering what's commercially used now and in the past) need to be sawn and machined prior to treating.

I couldn't agree more. I don't believe people should resaw treated material, if for nothing more than the fact that it won't last much longer than completely untreated material. They're usually expecting to get treated lumber for nothing, but it doesn't work that way. I was merely trying to advise the poster according to the question he asked without injecting my personal opinion.
BTW, old wood treated with organic preservatives makes fine boiler fuel as long as the boiler system has the proper scrubber/precipitator setup for this type of fuel. That makes a heck of a lot more sense than burying it in landfills, which is what usually happens.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor J:
I have been sawing creosote lumber for the last 10 years. I work in a landfill in a port city, and thousands of poles are dumped here every year from various places. We sawmill about 30 poles per day on average. All of the waste including the sawdust is recovered and dumped over a lined landfill. We are saving extremely valuable space, and have developed a lucrative buissness.

Horse farmers love creosote fencing - it will not rot and horses will not crib it. We use a mill with a remote, under a pole barn. We have learned to stay out of the flying dust, and we saw only in cooler weather when we are well clothed. I consider this a win-win business. It saves high dollar landfill space and we’re making good money for our product. Every pole I saw saves a tree from being cut down.