Information on Preservatives and Their Environmental Impact


 This page was developed to help anyone that may have questions better understand the different types of products currently being used in the  wood industry and their types of appications.  You will find here a glossary to better explain the difference between protectants and preservatives.  As an educated consumer, we hope to help you  make the right choice when considering any product being applied to your home. 
 This is here for you as a reference guide. Most of the products listed are in their chemical names,  so when using any product, look at the  effective ingredient list to determine what, if any, of  these chemicals are listed.


The American Wood Protection Association (AWPA) is a non-profit organization which is responsible for promulgating voluntary wood preservation standards. WPA's Standards are universally specified for wood preservation in the USA, and are recognized worldwide. 

Borates-Pesticides, Preservatives, EPA registered. Borates remain water soluble and readily leaches out in soil or rainwater. Borates are only to be used in applications where the wood is protected from the elements or the borate is sealed into the wood.  

Borate preservatives are sodium salts that are dissolved in water. Borates are effective preservatives against decay fungi and insects. Borate preservatives are standardized by the AWPA but only for applications that are not exposed to liquid water. Borate-treated wood should be used only in applications where the wood is kept free from rainwater, standing water, and ground contact. An example of such a use is in the construction of wooden buildings in areas of high termite hazard. Borates are also used in fire-retardant treatments.

Chromated Copper Arsenate(CCA)-Preservative, Pesticide, EPA registered, used mostly now in commercial applications.  May leach arsenic which is the  wood preservative.

A wood preservative used for timber treatment since the mid-1930's. It is a mix of copper, chromium, and arsenic formulated as oxides or salts. Over time small amounts of the CCA chemicals, mainly the arsenic, may leach out of the treated timber. The chemicals may leach from the wood into surrounding soil, resulting in concentrations higher than naturally occurring background levels.
Note: A number of countries have reviewed CCA during recent years and have looked at limiting the public exposure to CCA-treated timber by restricting its application in residential appications.

Copper naphthenate: Preservative, Pesticide, EPA registered, not a restricted use pesticide, but not recommended for use in marine appications

One of the copper compounds used as a wood preservative. Because of its relatively low acute toxicity to humans, it is considered a safer alternative to pentachlorophenol and creosote. Copper compounds, including copper naphenate, are highly toxic to aquatic organisms.  Naphthenates have a lingering and persisitent odor.   Also, copper accumulates in soils, and concentrates in marine and fresh water organisms.

Environmentally Friendly-

Considered to inflict minimal harm to the environment. 


The Environmental Protection Agency-A federal agency whose primary goal is to prevent or mitigate the adverse impacts of pollution on humanhealth and the environment. All persticides have to be E.P.A. registered.

Hazardous Waste-

By-products of society that can pose a substantial or potential hazard to human health or the environment when improperly managed. Possesses at least one of four characteristics (ignitability, corrosivity, reactivity, or toxicity), or appears on special EPA lists.

Mineral spirits:

Severe eye and skin irritant. Neurotoxic. Used in some floor cleaners, waxes, polishes, and many paints and related products. 

MSDS sheet-

Also known as a Material Safety Data Sheet- An MSDS sheet has  mandatory information that must accompany almost every chemical in the workplace. This information would include any hazards associated with the chemical and gives  information on its safe use, precautions and first aid procedures.

Petroleum Based-

Any material or substance derived from petroleum: fuels such as gasoline, of course, but also petrochmical  products such as synthetic textiles, plastics, and the ingredients of items as ordinary (and necessary) as medicines, foodstuffs, and household cleaners.


Any chemical or biological agent that kills plant or animal pests; herbicides, insecticides, fungicides, rodenticides, etc. are all pesticides.


Also known as Volatile Organic Compounds. These are compounds that have a high vapor pressure and low water solubility. Many are human made chemicals and are common ground-water contaminants.

 Water-based products

Either protective or decorative membrane-forming coatings that use water as the vehicle for application. They can be acrylic, epoxy, urethane sealers, or combinations of them.

Wood Preservatives-

Any chemical used to preserve wood. All wood presrvatives are considered pesticides. Most of the preservatives currently being used are limited to commercial applications. Wood preservatives poison the substrate and make the wood no longer a food source. 

Wood Protectants-

Products used for protecting and lengthening the life of wood. They are not all EPA registered as they don't all fall in the line as pesticides. They come as water and oil based also. Some of these products are environmentally friendly.   Any product that claims to have  a registered pesticide in it must BY LAW be EPA rigistered or it would be considered illegal to sell.

 Zinc Naphthenate:

Similar to copper naphthenate, a wood preservative. Relatively low toxicity, but zinc may have adverse effects on aquatic life. Usually formulated with petroleum distillates, which are probably responsible for major toxicity of products to humans.