A lack of understanding of food labels by consumers may put them at risk of poisoning.
Almost half of the respondents in a new survey did not know the difference between "best before" and "use by" dates.
Dr Thomas Quigley, of the Food Safety Promotion Board (FSPB), said: "Perishable food items should not, under any circumstances, be eaten past their `use by' dates."
This datemark is reserved for highly perishable foods. Using food beyond this point could put consumers' health at risk, according to the FSPB.
Most food can be safely kept longer than the "best before" date.
When this date runs out, it does not mean it is dangerous but it may no longer be at its best.
Two consumer surveys, one conducted in Northern Ireland by the Food Standards Agency, and published in January, and the other in the Republic by Research and Evaluation Services on behalf of the Food Safety Authority of Ireland (April 2001), and published by the FSPB, found that while good hygiene practices were increasing, a significant proportion of the Irish population was concerned about food safety.
There was some evidence of a change in beef consumption, with 28 per cent of the 1,000 respondents in the Republic, saying they had stopped eating mince and burgers.
Five per cent of people surveyed in the South reported they had suffered from food poisoning in the past 12 months, while 10 per cent of those in the North reported they had suffered from vomiting, abdominal pain, nausea and diarrhoea in the past 12 months.
Advice and results of the surveys from the FSPB's safe food helpline: 1 850 40 4567.