The Safetree programme was developed with WorkSafe, ACC and industry input as a response to the high number of accidents and fatalities over the past few years.
ACC also funded the programme.
''Contractor certification is one of the key areas of focus so we have a safe and professional industry'' Mrs Ewing said.
''It is about lifting safety standards.
''Safetree is not compulsory, but it is about industry leadership.
''Anyone can use Safetree, which is free, and if they sign up they will get regular newsletters and information updates.''
To date, 16 contractors nationwide had been certified and she was keen to see a 100% uptake in the industry.
''There are about another 80 or 90 more working their way through the process.''
She said while it was still early days for adoption, feedback had been positive.
The programme's auditors had gone to the work sites to talk to contractors and workers, and their feedback outlining what they considered were the real issues, was included.
-By Yvonne O'Hara