Due Diligence Defence (Food)

Section 21 of the Food Safety Act 1990 places the burden of proof on the defendant, not the prosecution: once a food safety offence is charged, it is 'a defence for the person charged to prove that he took all reasonable precautions and exercised all due diligence to avoid the commission of the offence by himself or by a person under his control.' In practice this means a business must show it had proper systems in place — supplier vetting, temperature and hygiene checks, staff training, product recalls and traceability records — and that the breach happened despite those systems, not because they were absent or ignored. For retailers, distributors and importers who neither prepared nor imported the food, section 21(3) offers an easier route: they can rely on the defence simply by showing the offence was due to the act or default of someone else outside their control (or to information supplied by that person), that they carried out reasonable checks on the food (or reasonably relied on the supplier's checks), and that they had no reason to suspect an offence was being committed.

The defence is not automatic if a defendant tries to blame another named individual or company: section 21(5) requires the defendant to serve a notice on the prosecutor identifying that other person at least seven clear days before the hearing (or within one month of first appearing in court, if later), unless the court gives leave to rely on the defence without having done so. Local authorities enforce food law against this backdrop using the statutory Food Law Code of Practice issued by the Food Standards Agency, which 'gives instructions that local authorities must consider when enforcing food law' — meaning how rigorously an inspector investigates a due diligence claim, and what evidence they expect a business to produce, is shaped by that Code as well as by section 21 itself. Because the defence turns on the adequacy of a business's own systems and record-keeping, businesses that cannot produce contemporaneous checks (delivery temperature logs, supplier assurances, cleaning schedules) are typically unable to make it out even where the underlying breach was genuinely not their fault.