With almost 400 products being swept off supermarket shelves amid the current Sudan 1 food dye scare, how can consumers be sure the food in their cupboards is safe?
Chilli powder is the culprit behind the latest food scare
Sudan 1 - mainly used in floor and shoe polish - was banned two years ago in the European Union as it had been linked to an increased risk of cancer.
The dye was used to brighten up chilli powder, which became an ingredient in a batch of Worcester sauce made by Premier Foods. That in turn was used to manufacture ready-made foods - ranging from chilli prawns to Pot Noodles - for dozens of retailers.
But with supermarkets controlling 80% of the UK's shopping baskets, such scares can "spread like head lice through a nursery" food campaigner Joanna Blythman says.
So how did the Food Standards Authority (FSA) know what foods were affected?
According to Food Chain magazine it was "traceability" - the new watchword in retail.
Philip Monument, head of research at Food Chain, says computers and barcodes can help maintain the checks and balances in the food supply chain.
"Supply data bases will keep track of who gave which products to a company," he said.
The technology revolution has allowed companies to trace transporters, packers and ingredients.
"Each one of these areas can be broken down again, for example you'd go to a directory for flavourings find the one you want and then you would get the information on amounts used, suppliers, batches and the time it was used."
This would trace the rogue ingredient down to a supplier which authorities would then swoop on and track it back up the chain to the shops.
And on the products it is not just barcodes, but other often colourful identifiers that allow to pinpoint the food with the dodgy ingredients.
In fact Asda says such systems made it possible for it to get all affected products off its shelves in "super quick time", spokesman Dominic Burch said.
"We have full traceability at the touch of a button, and had a full list of affected products within an hour," he added.
The British Retail Consortium (BRC) said it worked closely with trade associations, suppliers and retailers to ensure the products were removed from sale as soon as possible.
"A week ago we got word of this, we held meetings with the various groups all week to identify the products and the batches," spokeswoman Kate Ison said.
"The main thing now is that we're cascading information down to all retailers."
She added that the situation will be easier for large retailers as they will be able to track affected own-brand products, but with big name brands the information on what is affected is still coming through.
"We expect the number of affected products to get bigger and we'll just react to that."
But as far as the smaller local convenience stores and consumers themselves goes the story may be different.
Mr Monument believes that probably only half of the contaminated batch will be returned, some may already have been consumed while some shoppers may just throw the dodgy products away without asking to be reimbursed.
The FSA hopes to have a full list of affected products by Thursday
The Association of Convenience Stores is making sure all of its members have the full list of affected products and is "confident" its members are fully aware of the problem.
"It's such a big story that most stores do know about it anyway, but to make sure we're writing to all of our members as are the suppliers, manufacturers and so on," public affairs manager James Lowman said.
But he did admit there were some "knotty problems" for anyone not connected to the web and so unable to get a full list of the products contaminated with Sudan 1.
Small stores get their stock from a number of outlets. For some owners it may be difficult to remember from which cash and carry or wholesaler a particular sauce came from.
There should be no money worries, Mr Lowman added, wholesalers have made it clear they would reimburse businesses for returns.
But some of the affected products could already be on their way to other climes, for example glasses of Cross & Blackwell, which are a popular exported brand, Food Chain magazine warned.
"In five years' time it may still be on the shelves of some small Australian store, nearing its sell by date. Who's to say someone in the outback won't be splashing some of that sauce on their steak and thinking it tastes great," Mr Monument said.