This is some termite damaged timber that has been treated with Arsenic trioxide dust. You can see the remnants of the arsenic in the galleries in the timber, its bright red! Arsenic trioxide dust was introduced many years ago as a means of treating live termites in their workings in an attempt to eradicate the colony. Whilst it has been an effective means, arsenic trioxide is extremely toxic and there are much better methods nowadays that don't introduce toxic chemicals into your property. Termidor dust and baiting are just some methods that can be used. Unfortunately, arsenic trioxide is still readily available and still being used by pest controllers in Australia.
With 1 in 3 Australian houses being affected by termites, it's not uncommon for a house to have had a previous treatment, and while it's good that something has been done to deal with the termites, sometimes the residues of the treatment are far from safe.
Take Arsenic Trioxide for example.
This highly toxic substance has been used for many years to eradicate termite colonies, the main drawback however, is that this substance is left behind in the timber long after the termites have been eradicated.
To add insult to injury, it's mandated that notification be provided when arsenic is used to control termites in a building (as with many other termite treatments) however, during our inspections we seldom find any reference to any termite treatment in the meter box or anywhere else in the house. It's usually when we're confronted by the actual dusting that we first realise that arsenic dusting has taken place.
If you're worried that your home could have arsenic in the timber, make sure that you get a thorough inspection outlining if there has been any termite damage or treatments.