THE SAFETY OF CCA TREATED TIMBER

August 2001

The recent spate of articles in the media represent sensationalistic and unsubstantiated claims being made by the uninformed.

They appear as attempts not to be outdone by their competition and to join the host of similar messages, with which TV broadcasters are bombarding the public in the United States.

Media Reports have questioned the safety of CCA treated wood, giving the mistaken impression that it poses a health and environmental hazard.

These misconceived messages whether from magazines, TV, or any other medium are not scientifically based - in fact it is a pity that there was no purposeful contact with independent scientific experts who could have put the matter in perspective.

So ! What are the facts ?

In South Africa the issues are

- Is CCA treated timber safe ?
- What is the safety record ?
- Why do we treat timber ?
- What alternatives are there ?

IS CCA TREATED TIMBER SAFE ?

CCA treated timber can normally be identified by its slightly green colour. The components of CCA are copper / chrome / arsenic in a ratio which ensures that the preservative becomes ‘fixed' in the wood after it is impregnated into the wood by means of an industrial vacuum / pressure timber treatment plant. This fixation effect makes the CCA treatment in the wood highly leach resistant.

By the very nature of the function of a wood preservative it needs to be toxic to the agents which would otherwise attack the timber i.e. fungi and insects. Misrepresented apprehension about the use and effects of CCA treated timber are as a result of an inability to understand the significant difference between the actual preservative solution and the treated timber in which the preservative has become ‘fixed.'

The Environmental Protection Agency (EPA) in the United States conducted an eight - year investigation into CCA, the treatment process, the use and handling of the treated timber and the alternatives to the use of CCA. None of the EPA's investigations produced any findings showing increased risks of toxic effects on human (or of cancer) through the handling of treated timber. The EPA concluded that the benefits of CCA treated timber far outweighed any risks. Additional scientific studies from unbiased sources have addressed people's concerns over CCA treated timber, particularly in the area of exposure of children on playground structures and contamination to fruit and vegetables. These studies conclude that CCA treated timber is safe to use.

For many years, CCA treated timber has been used commercially in the growing of tomatoes, vines, bananas, mushrooms, etc. It is also used in the manufacture of fruit bins. No problems have ever been recorded and it has been substantiated that there is no migration of the preservative into the crop.

Critics who claim that CCA treated timber is life / health threatening have no scientific evidence to support their claim.

WHAT IS THE SAFETY RECORD OF CCA TREATED TIMBER ?

In South Africa each timber preservative is regarded, in law, as an agricultural remedy. All such agricultural remedies are required to be registered by the National Department of Agriculture (NDA). In the registration process there is consultation with the National Department of Health which is required to give its concurrence to the registration. CCA is manufactured in South Africa. Each of the manufacturers produces and distributes CCA under the strict requirements of its NDA registration certificate, which incidently is required by the NDA to be regularly renewed. Furthermore all the CCA produced in South Africa must comply with the relevant SABS standard. Moreover the treatment process must also comply with the requirements laid down in the SABS standard as also treated timber commodities.

CCA has been produced, sold and used throughout the world for the last six decades. During that time I conservatively estimate that some 400 000 000 cubic meters of CCA treated timber have been produced. To give this some meaningful evaluation, this quantity of timber would fit into more than 13 million Transnet railway trucks, which if connected one to another would circumnavigate the earth five times i.e. some 200 000 km. During this period of 60 years there has been no reported health problem caused by CCA treated timber. Certainly there is the occasional allergy problem experienced when sawing / drilling CCA treated timber, but this also arises with untreated timber.

CCA treated timber is a common product. We don't normally give its use a second thought.

CCA treated timber is an indolent material. It does not actively kill fungi nor insects when it is used. It is virtually an impassive product but is capable of resistance when it is attacked by these agencies. Its use is purely in a defensive capacity.

Arsenic is a naturally occurring element. It is the 20th most abundant element in the earth's crust and has been detected in virtually all evaluated foods. About 93% of the total arsenic exposure for most people occurs in food with water, air and soil, making additional contributions. Reports suggest that 90% of the 93% of the total dietary arsenic is contributed by seafood.

WHY DO WE TREAT TIMBER ?

Durable timber is a scarce and expensive commodity. Because of scarcity and cost one does not contemplate the use of a timber such as oak as a structural material in a building. In South Africa the vast majority of our commercial timber arisings are out of our plantation grown resources. Unfortunately these species of timber are not durable and if they are used in a situation where a predictable long term life is required or desirable then they need to be treated. The treatment of timber is nothing more than the application of sufficient suitable preservative to the timber so that the timber will perform in service as if it were a durable species.

Proper treatment of timber enables one to design and build with the necessary confidence that the timber will not be attacked by fungi and / or insects.

Treated South African exotic plantation grown timbers are extremely cost effective. They cost some 10% of what one would expect to pay for a durable construction hardwood from abroad. They are also cost effective when measured against other materials of construction such a steel, concrete, etc.

Additionally our home grown plantation timbers are required by law to be treated if used in construction in certain areas. These legal requirements are in place not only to protect the consumer but also to restrict the spread of timber destroying insects.

Life cycle assessments of forest products, including treated timber, continue to show timber in a light which should be beneficial in allowing its true potential to be recognised and realised.

Timber is the only renewable building material.

WHAT ALTERNATIVES ARE THERE ?

I believe that it is generally accepted in our industry that there are no known timber preservatives which are as cost effective across the whole range of hazards as CCA and Creosote.

Alternative products are available, but they are less effective and more costly. We keep track of what developments are taking place through ongoing contact and / or participation in the functioning of other preserving associations, treaters, chemical manufacturers, ISO and the International Research Group on Wood Preservation (IRG). There are a large number of alternative products being investigated and researched, but none of these are comparable with CCA and Creosote.

The ongoing international use of these two products is, however, subject to emotional judgement. It is articles like the one in Time Magazine which raise doubts - notwithstanding the facts, the safety record, the cost effectiveness and the desirability of continued use of CCA and Creosote.

The environmentalists, the legislators, the consumer are all reactive to the misplaced sensationalism we are seeing taking place - its newsworthy.

I believe that there will be change forced upon us in South Africa because of what is happening and will happen in America, Europe and Asia. Lets hope that in the interests of the industry, the consumer and good sound common sense that change happens later rather than sooner.

ANGUS CURRIE
Executive Director

AUGUST 2001