Many people who suffer an allergic or intolerant reaction to food (including anaphylaxis) do so after eating food from a catering business which has, ironically, a legal requirement to sell safe food and an implicit obligation to a duty-of-care toward their customers.

If a food sensitive customer becomes ill after eating in a food business, the business may be able to use the defence of due diligence in a subsequent prosecution if they can show that appropriate food-allergen controls were in place and working effectively at the time the incident happened on-site.

The defence of due diligence is acceptable in both the Republic of Ireland (ROI) and Northern Ireland (NI).

In NI, regulation 21 of the Food Safety Order NI 1991 introduced the idea of due diligence to food law. Where a person was charged with any offence under the Food Safety Order, they could now claim due diligence in respect of their food business if they could prove that they took ‘all reasonable precautions and exercised all due diligence’ to avoid committing an offence.

In ROI, paragraph 5 (3) (a) of European Communities (General Food Law) Regulations 2007 (S.I. No. 747 of 2007) refers to the due-diligence defence, particularly in relation to the offence of placing unsafe food on the market.