Farmers and others who use quad bikes or ATVs (all-terrain vehicles) while working are obliged from today to wear helmets and to undergo safety training.
The Health and Safety Authority (HSA) said the new quad bike law - the Safety, Health and Welfare at Work Regulation 2021 - is the first of its kind in Europe.
Quad bikes or ATVS are growing more common in farming and forestry operations. They are also used more frequently in road works, quarry and airport operations.
Over the last 13 years there have been at least 12 fatalities in agriculture involving quad bikes, and many serious injuries, according to the HSA.
HSA Senior Inspector for Farm Safety Pat Griffin said: "Too many lives have been tragically lost in quad bike incidents. Wearing a helmet and undergoing proper training has to be a basic requirement for any quad user."
"Machinery and vehicles, including quad bikes account for about half of all fatalities on farms. These new regulations can only benefit farmers and their families in trying to prevent future tragedy visiting our faming communities," he added.
Speaking on RTÉ's Morning Ireland, Mr Griffin that quad bikes have been a problem for many years, describing them as the most dangerous machine to operate in the country.
"We hope that making that change will reduce the number of fatalities and serious injuries happening on our farms and other workplaces." he added.
The new regulation obliges all ATV drivers to wear a motorcycle-type helmet or a specialist ATV helmet.
Helmets must have chin straps. Cycling helmets, workplace hard hats, and other helmets are not acceptable.
Mr Griffin said: "The wearing of helmets is a real, real problem and is probably the most important part of the solution.
"Most of the fatalities and life-changing injuries are because of a head injury.
"It makes sense that anyone operating a quad bike whether it's for leisure or for work wears a helmet.
"I would encourage people that use a quad bike for leisure also to do the training and always wear a helmet.
"It's just not worth taking the chance of a head injury."
Drivers must also complete an ATV safety training course. Those who are already experienced ATV users can do a one-day course while new drivers must complete a two-day course.
The HSA says the most common accidents that result in death or injuries include being thrown off the bike due to loss of control, collisions, being crushed or drowned under overturned bikes, and pedestrians being struck.
It said incidents are caused by lack of training, lack of helmets, speed, unbalanced loading and uneven terrain.
