He said the forestry industry would support the Government in any such campaign.
"The forest industry has no place for people who choose to live under the influence of drugs. We are a professional industry and, as such, drug-affected personnel are entirely inconsistent with the future of forestry."
Mr Kajavala said drugs had often been relegated to the too-hard basket in the past, but forestry had made huge strides towards a drug-free industry, adopting a very hard line.
"Zero drugs is the standard."
With their enjoyable forestry jobs at risk, he said forestry workers were choosing to get and stay clean and workers' attitudes towards drugs had changed.
Mr Kajavala pointed to a change in workplace culture, from being staunch and not wanting to dob in mates, to crews who now screen each other to make sure everybody measures up to the standard.
"The zero drugs standard is monitored using a range of testing, including pre-employment, post-incident, reasonable cause and random testing. Once detected, drug-affected personnel are placed into an employee assistance programme."
Mr Kajavala said everybody benefited when employees addressed their drug taking.
"Should the employee fail to make the necessary changes, they leave the industry."