Government figures show at least 52 forest workers were injured in the Wellington region in the last five years, which covers the Wairarapa.
Just last week in northern Wairarapa, 23-year-old Reece Reid died after a tree he had cut became entangled in another and fell on him.
On the same day, a 49-year-old worker had his legs crushed by a tree in the Kaingaroa Forest, near Rotorua.
Wairarapa First Union Organiser Dion Martin said the new code missed the mark.
"Workers put their lives on the line each day. We need to have better systems to protect them, and excluding them from participation in the development of new safety standards is not a good look," Mr Martin said.
CTU president Helen Kelly said the code was drafted with no worker input and reflected the industry's complete disregard for safety.
"We are absolutely outraged by these standards and we think it shows the Department of Labour has learnt nothing from the Pike River disaster."
In the last three years, 13 forestry workers had died on the job, Ms Kelly said.
Ministry of Business, Innovation and Employment injury figures show at least 871 forestry workers were hurt on the job in the past five years. At least five workers have died in accidents this year alone.
The CTU believed poor work conditions relating to fatigue and long hours were a major contributor to the forestry industry's high accident rate.
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.
"This is an approved code, which means it actually carries greater weight than just a best practice guide," he said.
"[Employers] do not have to follow the rules exactly, but you have be able to prove that if you have not performed an action according to the code, you have another system in place that is just as good."
Mr McClay said the code would help towards reaching the Government's 2020 goal of reducing workplace deaths and serious injuries by at least 25 per cent.