Preservative Numbers

Many different preservatives have been approved in the timber treatment standard NZS 3640:2003, for use in timber treatment in New Zealand.

The preservatives have different qualities and properties and are therefore suitable for different applications.

Preservatives are carried in either water or white spirits in order to achieve penetration into the wood.

Each approved preservative is identified by a unique number which is incorporated into the brand marked on treated timber (see under WOODmark).

The numbers are:

CCA Oxide

01

CCA Salt

02

Boron

11

TBTO

56

Copper Naphthenate

57

Copper Azole

58

TBTN

62

IPBC

63

Propiconazole + Tebuconazole

64

Permethrin

70

Alkaline Copper Quaternary

90