There is a need to develop wood preservatives based on low toxicity, low environmental impact chemicals, particularly for the residential market as the general public becomes more aware of the chemicals currently in use. Although the health hazards of treated wood may be negligible, the public perception of potential hazards may be sufficient to proscribe the future use of the present chemicals. Opportunities also exist in overseas markets for boron treated lumber provided that a rapid and cost effective diffusion process can be developed. The proposed approach to this problem, and progress made in 1991/92 are discussed.