The document summarizes information about the wood preservative C12-16-ADBAC. It describes C12-16-ADBAC as a fungistatic and insecticidal cationic surfactant active substance used for preventive protection of wood against wood destroying organisms and fungi. Its mode of action involves destroying cell walls and membranes. The biocidal product BQ-25 contains 25% C12-16-ADBAC and is used to treat wood through drenching or vacuum pressure processes at a concentration of 0.4-2.0% C12-16-ADBAC. The risk of developing resistance to C12-16-ADBAC is considered negligible as it prevents growth rather

1. WOOD PRESERVATIVE
Wood treated with C12-16-ADBAC-containing biocidal product is not intended for and contains label
restrictions against use in areas where food for human consumption is prepared, consumed or stored, or
where the feedingstuff for livestock is prepared, consumed or stored. Therefore, no analytical method
for the determination of residues in food/feed of plant/animal origin is required, either.
The active substance Alkyl (C12-16) dimethylbenzyl ammonium chloride (C12-16-ADBAC) in Type 8
products acts as a fungistatic and an insecticide. It is used for preventive protection of wood and
constructional timbers in Hazard Classes 1 to 4A according to ISO draft standard.
Effectiveness C12-16-ADBAC is a cationic surfactant type active substance. Since it is surface active, it
has fair wetting properties and reacts strongly with cell walls of micro-organisms. Its mode of action,
therefore, is to destroy the cell walls by sticking on the exterior structures and by entering and
disintegrating the inner phospholipid-bilayer-based membrane structures. Due to its interaction with
phospholipid-bilayer-based structures, it severely alters the cell wall permeability, disturbs membrane-
bound ion-translocation mechanisms and may facilitate the uptake of other biocides.
The field of application of Alkyldimethylbenzylammonium Chloride includes wood preservatives for the
preventive treatment against wood destroying organisms and against wood discolouring moulds and
fungi. The use concentration depends on the type of application technique, use class required, and on
additional formulation components.
Quaternary amine (quat) biocides in the wood preservation market are always used in formulations in
combination with other active substances. Efficacy studies with quats alone require considerably higher
concentrations than those actually used in these formulations. Therefore, the use of “quat only” efficacy
data for risk assessment may provide an exaggerated environmental exposure level.
Against fungi, a selective activity spectrum exists.
The biocidal product (BQ-25) contains 25% Quaternary ammonium compounds, benzyl-C12- 16-
alkyldimethyl, chlorides in water.
It is used in drenching/dipping and vacuum pressure process applications. In practice it is always used in
formulations in combination with other active substances.
The biocidal product concentrate is diluted to a suitable working strength with water. The degree of
dilution will vary depending on the wood species, type of wood product and anticipated use. The
requirements for the final concentration of C12-16-ADBAC vary between 0.4% and 2.0%. The application
rate of C12-16-ADBAC in wood is 2.0 kg/m3 . Number and timing of applications depends on application
technique, wood species, moisture and hazard class. An uptake of approximately 2.0 kg/m3 should be
achieved by these application methods in order to ensure the protection level for the different use
classes required. BQ-25 is used for preventive protection of wood and constructional timbers in areas
with moderate or subtropical climate in Hazard Classes 1 to 4A according to ISO draft standard

2. Since after approx. 40 years of use worldwide no reports of selective acquisition of C12-16- ADBA-
resistance in the field of wood protection exists, the risk of development of resistance to is considered
negligible. On the other hand, C12-16-ADBAC as a wood preservative works by preventing growth of
organisms, not by killing organisms that are present thus reducing the potential for resistant organisms
to develop. In addition, for hard surface sanitization/disinfection (where antimicrobial activity is based
on direct killing of organisms present on surfaces), investigations on exposure of domestic microbial
communities to quaternary ammonium biocidal substances showed no increased antimicrobial
resistance (McBain A.J. et al. 2004). Therefore, we can agree that development of resistance can be
considered negligible.
Reported by Sarana Mitra Inti Global Pte Ltd
www.sanminglobe.blogspot.co.id
Michael
sanmin_global@yahoo.co.id