Accepted timber permanent preservative formulations

These timber preservatives are mixtures of various compounds of copper, chromium and arsenic.

Preservatives of this type must be formulated from either salts or oxides of bivalent copper, hexavalent chromium and pentavalent arsenic. In the formulated preservative and the solution used to treat the timber, the ratio of these active elements shall fall within the following limits

• Copper: 23-25%
• Chromium 38-45%
• Arsenic 30-37%.

The minimum concentration of CCA-type preservative in the zone required to be penetrated shall be 0.320% mass/mass (elemental copper + elemental chromium + elemental arsenic) based on the oven dried mass of the wood. This is deemed to be the minimum retention requirement.

Calculation of preservative retentions relies on a number of assumptions. These are listed in the example below. Minimum retention for each CCA preservative may be calculated as follows:

1. Each elemental concentration of copper, chromium and arsenic is converted to the form in which it appears in the formulation, i.e.
   • %Cu to % Cu formulation e.g. % Cu to % CuSO₄.₅H₂O
   • %Cr to % Cr formulation e.g. % Cr to % K₂Cr₂O₇
   • %As to % As formulation e.g. % As to % As₂O₅.₂H₂O
2. Formulation concentrations are then added to provide a Total Formulation Value (TFV); i.e.
   • % CuSO₄.₅H₂O + % K₂Cr₂O₇ + % As₂O₅.₂H₂O = %TFV
3. The % TFV is then multiplied by the wood density/100. In the absence of more detailed information, 500 kg/m3 may be assumed as the wood density value for Pinus timbers and 1000 kg/m3 assumed as the value for hardwoods, therefore;
   • %TFV x wood density/100 = piece retention

In general, piece retention is about 60% of charge retention and so Charge retention = piece retention x 1.6.

The CCA timber impregnation preservative formulations that appear in Table 2.1.1 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

Note: Basilit C, Basilit CCA type A, Basilit UA, Basilit CCA type B and Basilit UA No. 132 are no longer manufactured

The minimum concentration of copper, chromium and fluorine in the zone required to be penetrated shall be 0.56% mass/mass (elemental copper + elemental chromium + elemental fluorine) based on the oven dried mass of the treated wood.

Preservatives of this type shall be formulated from either salts or oxides of bivalent copper and hexavalent chromium. In the CCF formulated preservative and the solution used to treat the timber, the ratio of these active elements shall fall within the limits:

• Copper: 30% minimum
• Chromium 50% minimum
• Fluorine 5% minimum.

The CCF type preservatives that appear in Table 2.1.2 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

*TAE or Total Active Elements is the sum of the copper, chromium and fluorine components of the formulation.

Ammoniacal copper quaternary timber preservatives are mixtures of compounds of the element copper and quaternary ammonium. The quaternary ammonium compound may be either didecyldimethyl ammonium chloride (DDAC) or benzalkonium chloride (BAC).

In the DDAC formulated preservative or DDAC preservative solution used to treat the timber, the composition of the active ingredients must fall within the limits (see AS1604):

• Copper 57 - 66%
• DDAC 33 - 44%

In the BAC formulated preservative or BAC preservative solution used to treat the timber, the composition of the active ingredients must fall within the limits:

• Copper 45 – 66%
• BAC 33 – 54%

The minimum concentration of this type of preservative in the zone required to be penetrated shall be 0.350% mass/mass (elemental copper + DDAC or BAC) based on the oven-dried mass of the treated wood.

The ammoniacal copper quaternary preservatives that appear in Table 2.1.3 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

These timber preservatives are a mixture of boric acid and dialkyldimethylammonium chloride (DDAC) and are accepted for their DDAC content and not the borate component (which has not been shown to be equivalent to Hazard level 2 as per Australian Standard AS 1604).

Treated timber must contain not less than 44% of the minimum retention as DDAC. The minimum concentration of this type of preservative in the zone required to be penetrated shall be 1.56% mass/mass (elemental boron + DDAC) based on the oven dried mass of the wood. This shall be deemed to be the minimum retention requirement.

The boron and alkyl ammonium type preservatives that appear in Table 2.1.4 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

Copper azole wood preservatives are a mixture of copper and triazole compounds. In the formulated preservative and the preservative used to treat the timber, the concentration of the triazole expressed as a percent of total active ingredients shall fall within the following limits:

• Tebuconazole 4.18% - 3.42%
• Cyproconazole 1.64% – 1.34%

The minimum concentration of this type of preservative in the zone required to be penetrated, shall be:

• 0.27% mass/mass (elemental copper + Tebuconazole), or
• 0.38% mass/mass (elemental copper + Cyproconazole),

based on the oven dried mass of the wood.

The copper azole preservatives that appear in Table 2.1.5 are acceptable as biosecurity treatments for solid timber and unbonded veneers.

Cu-HDO wood preservatives are a mixture of copper compounds, HDO and boric acid.  In the formulated preservative and the preservative used to treat the timber, the composition of the ingredients (must be expressed as a per cent of total active ingredients) shall fall within the following limits:

• Copper  70-75%
• HDO  19-24%
• Boron  5-7%

The minimum concentration of this type of preservative in the zone required to be penetrated must be 0.255% mass/mass (elemental Cu+HDO+B) based on the oven dried mass of the wood. This shall be deemed to be the minimum retention requirement.

The Cu-HDO and boric acid preservatives that appear in Table 2.1.6 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

These preservatives are a mixture of copper compounds, boric acid and polymeric biocides. These active ingredients combine synergistically to give both insecticidal and fungicidal efficacy.

The Copper, Boric acid and Polymeric biocide preservatives that appear in Table 2.1.7 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

This type of preservative may be used by itself or with a fungicide and is usually dissolved in an organic solvent such as white spirits.

The minimum concentration of this type of preservative in the zone required to be penetrated must be 0.020% mass/mass (permethrin) based on the oven dried mass of the wood.

The timber preservatives containing permethrin that appear in Table 2.2.1 are acceptable biosecurity treatments for solid timber and unbonded timber veneers.

This type of preservative may be formulated by itself or with a fungicide and is usually dissolved in an organic solvent such as white spirits. The minimum concentration of this type of preservative in the zone required to be penetrated must be 0.0020% mass/mass (deltamethrin) based on the oven dried mass of the wood or a minimum retention of 0.03kg/m³. This is the minimum retention requirement.

Note: Formulation names for preservatives containing the active ingredient deltamethrin are not listed.

The minimum preservative retention of this type of preservative in the zone required to be penetrated must be 0.030% mass/mass (cypermethrin) based on the oven dried mass of the wood. 

This is the minimum retention requirement.

The timber preservatives containing cypermethrin that appear in Table 2.2.3 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

A preservative which in addition to achieving adequate penetration has a minimum retention of 0.18 kg/m³ fenvalerate*.

*The minimum charge loading of commercial preservatives based on treated wood volume.

A preservative which in addition to achieving adequate penetration has a minimum retention of 4.8kg/m³ tributyltin oxide*. (TBTO is a Fungicide only and is only acceptable when formulated with an acceptable insecticidal timber preservative).

*The minimum retention of commercial preservatives based on treated wood volume.

A timber preservative which in addition to achieving adequate penetration has a minimum retention of 0.42 kg/m³ fenitrothion*. The following commercial formulation at a minimum charge retention indicated in brackets is an acceptable as biosecurity treatment:

Koshiace B (2.0 kg/m³)*.

*The minimum retention of commercial preservatives based on treated wood volume.

The timber preservatives containing Chlorfenapyr that appear in Table 2.2.7 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

The timber preservatives containing Bifenthrin that appear in Table 2.2.8 are acceptable as biosecurity treatments for solid timber and unbonded timber veneers.

Timber preservative formulations containing Phoxim® that appear in Table 3.2.1 are acceptable as biosecurity treatments for plywood and LVL.

Treatment certificates must state veneer thickness.

Timber preservative formulations containing Chlorfenapyr that appear in Table 3.2.2 are acceptable as biosecurity treatments for plywood and LVL.

Note: For Meganium 2000 and Wolsit T-20, efficacy tests were conducted on Keruing (Dipterocarpus spp.) and European beech (Fagus sylvaticus). Accordingly these two formulations are onlyaccepted as a glueline treatment for plywood manufactured from hardwood substrates. Tailileum 200 has not been tested for European beech and therefore it is not accepted for use with this species.

Treatment certificates must state veneer thickness.

Timber preservative formulations containing Imidacloprid that appear in Table 3.2.3 are acceptable as biosecurity treatments for plywood and LVL.

Note: Efficacy tests for Protecta C-02, Supraleum 150 and Supraleum 75/OPP were conducted on Keruing (Dipterocarpus spp.) and European Beech (Fagus sylvatica) plywood. Accordingly, these formulations of Imidacloprid are only accepted as a glueline treatment for plywood manufactured from hardwood substrates. Tailileum 400 was tested on Keruing/ Eucalyptus plywood and birch/ larch plywood. 

Treatment certificates must state veneer thickness.

Timber preservative formulations containing Bifenthrin that appear in Table 3.2.4 are acceptable as biosecurity treatments for plywood and LVL.

Note:  The formulation of Bifenthrin is accepted as a glueline treatment for plywood/LVL manufactured from both softwood (coniferous) and hardwood substrates. For Supraleum 2006 Bi 50, efficacy tests were conducted on Keruing (Dipterocarpus spp.).

Treatment certificates must state the veneer thickness.

Timber preservative formulations containing Cypermethrin that appear in Table 3.2.5 are acceptable as biosecurity treatments for plywood and LVL.

Note: Efficacy tests for Radaleum FAP and Radaleum HP were conducted on Radiata pine (Pinus radiata D. Don) plywood. Accordingly, the above Radaleum FAP and Radaleum HP formulations of Cypermethrin are only accepted as a glueline treatment for plywood/LVL manufactured from softwood (coniferous) substrates. Radaleum FHP – 60 has been tested on both softwood and hardwood plys.

The efficacy tests for the above Tailileum 300, Cypermethrin and Alpha-cypermethrin formulations were conducted on keruing plywood. Therefore it is only accepted for use in hardwood substrates. Tailileum 300 formulations containing beta-cypermethrin are not accepted by the department.

Treatment certificates must state the veneer thickness.

Formulations containing Neonicotinoids that appear in Table 3.2.6. are acceptable as biosecurity treatments for softwood plys and LVL.