Contaminated feed from the Republic has been fed to herds of cattle on eight farms in Northern Ireland.
The North's Food Standards Agency (FSA) said today it had established that eight farms had used feed from the Millstream Recycling plant in Carlow which is at the centre of a major dioxin scare.
But the agency said the contamination would not get into the food chain.
FSA deputy director in Northern Ireland Maria Jennings said: "All of those herds have been placed under restriction, which means that none of the meat from those herds will go into the food chain."
She said: "The beef that is on sale in Northern Ireland is entirely safe, there is no problem with that meat on sale on the supermarket shelves."
The agency said no pigs in the North had been given the contaminated feed and that processors in Northern Ireland could start slaughtering pigs again.
Ms Jennings said: "We are quite happy that the processors can start to process Northern Irish pigs, it is safe and can be put on the shelves."
She said the pork should be in the shops within a couple of days.
Meanwhile, results from tests carried out on beef at 38 cattle farms in the Republic which also used the contaminated feed are expected back later today.
The chief veterinary officer of the Department of Agriculture Paddy Rogan yesterday said plans were being drawn up to slaughter and destroy 100,000 pigs which were being held on the 10 pig farms on which contaminated feed was used.
The recall followed the discovery of potentially dangerous dioxins, known as PCBs, in pigmeat in routine tests undertaken last week. The tests showed pork with dioxin levels of 80 to 200 times above the safety limits.
According to an investigation which is being conducted by the Environmental Protection Agency (EPA), the Millstream Recycling plant in Carlow, which is at the centre of the inquiry into contaminated pork, used "inappropriate" oil in the process used to make pig meat.
The recall has led to pig processors laying off hundreds of workers and putting others on protective notice.
The president of the Irish Farmers Association (IFA) Padraig Walshe said today that farmers were anxiously waiting for the results of the cattle tests.