Chromated copper arsenate (CCA) treated timber in schools

Find health and safety information about CCA and advice for managing the risks at school.

Level of compliance Main audience Other


  • Boards
  • Proprietors
  • Building Contractors
  • Principals and Tumuaki
  • Project Managers

Timber treated with Chromated Copper Arsenate (CCA) is a potential health risk because it contains arsenic. Boards need to manage this risk, especially in the playground.

Meeting your health and safety responsibilities

Managing hazardous substances at your school is part of your overall health and safety responsibilities. We recommend you review your school’s health and safety systems.

This will help you meet the requirements of the Health and Safety at Work Act 2015(external link).

Using timber treated with chromated copper arsenate

Chromated copper arsenate (CCA) treated timber is also known as tanalised wood.

CCA is a preservative made of chemical compounds containing copper, chromium and arsenic. Since the 1930s, it has been used to treat wood to stop it rotting in outdoor settings.

In schools, CCA treated timber is often used in:

  • a playground
  • the wood around a sandpit, or
  • a deck.

Managing the risks of CCA

Chromium, copper and arsenic all occur naturally in the environment. These substances are only a health risk if people are exposed to large amounts over a certain period of time. Exposure includes swallowing, inhaling or skin contact.

A report by the Environmental Protection Authority (EPA) states that, while arsenic is a known human carcinogen, and should be avoided, CCA-treated timber does not pose significant risks to the public.

You can read EPA’s information sheet Questions and Answers on Copper Chromium Arsenic (CCA) Treated Timber, which includes advice on applying sealing products to CCA-treated timber. 

The EPA does not recommend replacing or removing existing structures made with CCA-treated timber or the soil surrounding those structures.

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