Many people have heard that treated pine sleepers may have the infamous poison arsenic in them and are concerned that they might not be safe to use for landscaping or construction needs.

In this post, we’ll talk about why the concern exists, how serious it is, and how you can be sure that no arsenic finds its way into your soil.

treated pine sleeper

At Narangba Timbers, we sell two types of pine sleepers. Let’s take a look at what those two types are, and it should be a bit clearer which you should choose for your project.

Copper Chrome Arsenate Treated Pine (CCA)

The most common preservative used for wood timbers is copper chrome arsenate (CCA). This is a mixture of copper, chromium, and arsenic that is used to protect the wood from insect and fungal attacks.

While it is fine for many construction needs, the presence of arsenic has caused concern that uses of the wood which results in frequent contact might not be safe.

The Victoria State government even cautions against its use for a variety of applications.

Alkaline Copper Quaternary Treated Pine (ACQ)

As you can probably tell from the name, alkaline copper quaternary (ACQ) treated wood does not contain arsenic.

ACQ treatment still uses the cooper but replaces the arsenic and chromium with an alkaline of quaternary ammonium.

If you are concerned that your construction project will expose you or your loved ones to arsenic, then this is a low cost, long-lasting alternative.

ACQ treated sleepers look the same as their CCA counterparts, but are safe for use in projects that will see frequent human contact.


CCA treated wood still has its uses and is still a very fine choice for projects such as wall framing or farm fencing that will not see much human contact.

For projects that you will be interacting with a lot, such as playgrounds and picnic tables, ACQ is an option that will ensure you are not exposing anyone to arsenic.

You may even enjoy the peace of mind that ACQ gives for those projects that will see less frequent but still common contact, such as flower bed framing or pergolas.

If you have any questions about the best sleeper for your project, please do not hesitate to contact Narangba Timbers.