What it is
E901 is beeswax: the natural wax secreted by worker honey bees to build the cells of their honeycomb. Comes in two refined grades — white (bleached) and yellow (unrefined).
Why it matters
Used as a glazing agent on confectionery and chocolate, in chewing gum, as a polish on fresh fruit, and widely in cosmetics — lip balms, mascaras, hair pomades. Also appears in wax-lined paper cups and some pharmaceutical coatings.
What to do
Always not vegan. Plant-based alternatives include candelilla wax (E902) and carnauba wax (E903), both from plants — though check individual products, as some formulations blend the two with beeswax.