Approved Document D
Toxic substances
About Approved Document D
Approved Document D gives guidance on protecting people from toxic fumes given off by insulation material inserted into a cavity wall. It is a short document that sets out the performance expected and the standards it refers to.
What it covers
- Toxic fumes from cavity wall insulation
- Use of urea formaldehyde foam as cavity insulation
- When the guidance applies and the performance expected
- Standards referred to
Approved Document D: toxic substances
Welsh Government