Horseradish

What it is. A bright white pigment used to make sweets, icing, sauces and coatings look opaque and white.

Why it is used. Purely cosmetic. It changes appearance, not taste or safety of the food.

What the evidence says. In 2021 the EU food safety body EFSA concluded it could no longer be considered safe as a food additive, mainly because possible genetic damage from the tiny particles could not be ruled out. That is a precautionary call rather than proof of harm in people.

Banned as a food additive in the EU since 2022. Still permitted in the UK and the US, which reached different conclusions on the same evidence. A clear case of the same additive, different rules.

Assessed against EFSA, UK FSA, US FDA. Full entry for E171

What it is. The potassium salt of sorbic acid, which stops mould and yeast growth.

Why it is used. Used in cheese, baked goods, dried fruit, wine and dressings.

What the evidence says. Widely used and long regarded as one of the gentler preservatives. EFSA's 2015 re-evaluation lowered the acceptable daily intake and noted gaps in the genotoxicity data, asking for more work, while finding no evidence of harm at the levels actually used.

Permitted with maximum levels. EFSA has asked for further data rather than restricted it.

Assessed against EFSA. Full entry for E202

What it is. A fibre made by fermenting sugars with a bacterium, which thickens liquids at very low doses.

Why it is used. Thickens sauces and dressings and gives structure to gluten free baking.

What the evidence says. Passes through largely undigested and is treated as safe by regulators, with no numerical intake limit. Very large amounts act as fibre does, which is a digestive effect rather than a safety one.

Permitted freely.

Assessed against EFSA, JECFA. Full entry for E415