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
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.
Packing size 25 kg/pail, 200 kg/drum.
