The Saturday run to the supermarket will have a rather different quality to it this morning. At the urgent request of the Food Standards Agency (FSA), shelves will have been cleared to prevent customers being exposed to more than 350 products believed to be contaminated with Sudan 1, a red dye that is linked to an increased risk of cancer. The level of additional risk is, in truth, very small and even the most passionate enthusiast for Worcester Sauce is unlikely to have been made ill by the product. It is, however, proper to alert the public to their possible exposure to a substance that has been banned in food throughout the EU since 2003.

The details about how this scare occurred and at what stage it might have been detected earlier are still sketchy. An element of bad luck as well as incompetence might well be at play. The Sudan 1 entered a batch of chilli powder which was then used to produce a substantial consignment of Crosse and Blackwell Worcester Sauce at the behest of Premier foods. From there it was passed on to be included in some 359 separate foodstuffs. It came to light only after tests conducted not in Britain but by the Italian authorities.

It is not clear exactly what notice the company concerned had and the speed at which it alerted the major supermarkets and the FSA. It would be wrong to rush to judgment as to whether it acted properly at this stage. All food companies should have been unusually vigilant about this chemical. The FSA has issued scores of alerts relating to Sudan 1 in the course of the past two years, although until yesterday these had related to rather obscure brands in specialist outlets. Even so, it does appear that there was always some danger that this dye might be discovered in mainstream fare.

The concern is whether the FSA has moved as promptly as appropriate. It seems to have been aware of this scare as early as Monday of this week, yet four days passed before the alarm was sounded to consumers. The FSA was, in fairness, in something of a bind. It knew that the risk to health was small but that the response when the alarm was raised might border on hysteria. It was also unsure how many different products were affected and decided that a delay to compile a comprehensive list was better than having to update that list day after day.

These are difficult decisions. But as a rule, it must be assumed that the public is entitled to more rather than less information, and that most adults will respond reasonably intelligently when it is said that foods are being recalled as a precautionary measure. The FSA may thus have compounded an existing image problem. It has previously been accused, perhaps unfairly, of preferring to “sort out” problems such as these behind the scenes with the large retailers and only then bring the consumer into the conversation. It was this tendency that ultimately discredited the old Ministry of Agriculture and led to its de facto abolition.

The best strategy for the FSA now is absolute candour. It should be totally open about when it received what information, who it chose to contact and why it proceeded as it did. On the face of it, a sudden announcement in the middle of the Friday before the weekend shopping rush does not look like a triumph of public relations planning. It might have been the least bad route to adopt, but it demands explanation. Sudan 1 in these foods is not life-threatening. Leaving the public in the dark, though, may be damaging for the FSA.