Sodium sulphite (E221)

No. Sodium sulphite (E221) is not one of the markers Open Food Facts uses to classify a food as processed or ultra-processed, so on its own it doesn't raise a product's NOVA group.

What it is

Antioxidants are substances which prolong the shelf-life of foods by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes.

A product that contains it can still be ultra-processed for other reasons: 35 of the 48 products here that contain sodium sulphite (E221) (73%) are in group 4 because of other ingredients or additives.

Function

Antioxidant: Antioxidants are substances which prolong the shelf-life of foods by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes.
Preservative: Preservatives are substances which prolong the shelf-life of foods by protecting them against deterioration caused by micro-organisms and/or which protect against growth of pathogenic micro-organisms.

Functional class definitions from the EU food additives regulation, via Open Food Facts.

More about sodium sulphite (E221) on Wikidata

Where it turns up

Sodium sulphite (E221) appears in 48 of the 40,000 products on this site (0%).

Pork sausages 6 of 55 products
Crackers (Appetizers) 5 of 715 products
Chipolatas 4 of 27 products
Sausages 4 of 337 products
Beef hamburgers 3 of 17 products
Plain salty snacks 3 of 20 products

Products containing sodium sulphite (E221)

How the NOVA classification works