The firm’s “safety differently” policy focuses on preventing fatalities rather than all accidents however minor.
Ucatt believes the policy could “erode the very foundations of the UK’s health and safety culture.”
UCATT Midlands Regional Secretary, Shaun Lee, said: “Small injuries are not small concerns for workers.
“By neglecting basic safety, we put workers’ health and futures at risk.
“Small injuries can mean significant loss of pay and significant psychological stress for the worker and their family.
“If we don’t have zero tolerance in the work place, then standards will slip and the number of injuries will increase.”
An O’Rourke spokesperson said: “UCATT has not approached us with any concerns regarding “safety differently” and today’s press release is the first time we’ve heard of them.”
Safety differently is being driven by Group’s Health and Safety Director John Green who has seen the success it enjoyed in Australia.
The spokesperson said: “There’s a focus at many organisations on low-consequence events, like twisted ankles, in the belief that they prevented high-consequence events.
“In other words, the prevention of all harm means the prevention of serious harm. We do not believe that is true.
“There is no correlation between the number of times people twist their ankle and whether or not someone’s going to get killed by falling from height, for example.”
Former Vinci health and safety director Andy Sneddon is joining O’Rourke next month to head up safety across Europe.
The spokesperson added: “There’s also a new emphasis on seeing Laing O’Rourke’s own people as the solution to health and safety challenges by involving them in deciding how hazardous work should be approached.
“Instead of being all paperwork and process, we want health and safety to be at the very core of what we do – and how we do it. In other words, safety is an ethical responsibility not a bureaucratic activity.
“It’s not a question of saying everything we’ve done in the past was wrong – it absolutely isn’t. We wouldn’t be where we are now without it.
“It’s about building on that foundation with a new approach that will take us in the direction we want to go.”