Instant Fish Sauce With Garlic, Chilli

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. Vitamin C, added to protect colour and flavour and sometimes to fortify.

Why it is used. Stops browning in juices and cut fruit, protects fats, and boosts vitamin content.

What the evidence says. Beneficial and harmless at the levels used. Included here as a reminder that an E number is just a code, and plenty of them are ordinary nutrients.

Permitted freely, no concern.

Assessed against EFSA, JECFA. Full entry for E300

What it is. The sodium salt of glutamate, an amino acid found naturally in tomatoes, cheese and mushrooms.

Why it is used. Boosts savoury, umami flavour in stocks, crisps, ready meals and sauces.

What the evidence says. The old idea of MSG causing headaches and flushing, once called Chinese restaurant syndrome, has not held up in controlled trials. Regulators worldwide treat it as safe at normal intake. A genuinely useful example of a feared additive that the evidence exonerates.

Permitted and classed as safe. Adds to total sodium, so it counts towards salt if a product uses a lot.

Assessed against EFSA, JECFA, US FDA. Full entry for E621