I have just listened to a wonderful little radio program on Frederick Accum and Food Safety in 1820. It is the first episode in a 5-part adaptation of Bee Wilson's Swindled: From Poisoned Sweets to Counterfeit Coffee being run as the BBC Radio 4 Book of the Week. Recordings of the episodes can be found here for a week after they have been broadcast. Accum used the methods of the then relatively new science of chemistry to uncover the widespread use of poisonous substances in foodstuffs in early 19th Century England. He wrote a book on the subject:
A Treatise on Adulterations of Food, and Culinary Poisons, Exhibiting the Fraudulent Sophistications of Bread, Beer, Wine, Spiritous Liquors, Tea, Coffee, Cream, Confectionery, Vinegar, Mustard, Pepper, Cheese, Olive Oil, Pickles, and Other Articles Employed in Domestic Economy
You can find a copy here. Accum also played a part in the introduction of gas-lighting to London. I think his name deserves to be more widely known.