It is a wood preservative treatment that protects against decay fungal /insect attack It is a treatment that is much more friendly to people and the environment, than Creosote, that was banned in 2003. See Treatments.
The timber is treated using pressure impregnation with a water based preservative, complying with BS 4072
Treated timber has a green or natural pine colour.
When impregnated into the timber the chemical components become fixed within the wood structure and are leach resistant.
Usually specified for general construction and outdoor timbers
Believe it or not, the treatment companies (and hence us!) offer NO GUARANTEE at all as to the treatment and the longetivity of the timber. They argue that the way timber is used and constructed is in so many different applications and settings (above ground, under ground, in water etc...) not to mention timber naturally splitting and moving, and being cut, drilled into etc.. that they cannot guarantee or predict how long the timber will last and how long the treatment will be effective.
In reality, like many companies, they are frightened about people making claims against them, and so chose to offer no guarantee, rather than risk someone wanting the whole of their fencing to be replaced after 10 years, if it starts to rot.
Although we all know that pressure treated timber will last considerably longer than 2 days (!) we are unable to say or guarantee how long it will last. Sorry.It's all very unsatisfactory, but it's the way of the world !