However, the code lacks regulatory force as employers are not legally required to comply.
Northland First Union organiser Garry Hetherington said worker involvement in safety standards was paramount.
"Too many people in our forest industry are dying and injured.
"Workers and their union should be more actively involved in the development of these safety standards," he said.
A 21-year-old worker was transferred to Auckland Hospital in October after being hit by a log while working in pine forest near Awarua, south of Kaikohe.
Less than three weeks earlier, a log rolled on to a worker in a forestry block south of the Mangamuka Ranges.
Combined Trade Unions (CTU) president Helen Kelly said the code was drafted with no worker input and reflected the industry's complete disregard for safety. "By promulgating these standards in the manner that they're written, they're basically now complicit in the dangerous practices in the forestry industry," she said.
The CTU believed poor work conditions relating to fatigue and long hours were a major contributor to the forestry industry's high accident rate.
Standards that held employers accountable for poor safety practices had to be enforced, Ms Kelly said.
Glen Mackie of the Forestry Owners' Association helped formulate the new code, which focuses specifically on tree-felling and breaking out - the process of removing a tree from the forest - the most common causes of serious injuries.
Mr McClay said the code of practice would help towards reaching the Government's 2020 goal of reducing workplace deaths and serious injuries by at least 25 per cent.
Forestry worker injuries - January 2008 to April 2012
Northland 84
Bay of Plenty 100
Manawatu-Wanganui 66
Hawke's Bay 40
National 871