The most important conceptual point for this page — the distinction between additive status and novel food status, since these are two separate legal categories that can both apply to the same substance for different uses.

The alginates/carrageenan/agar family (E 400–407) is given prominent treatment as, by volume and value, the dominant established commercial use of algae as food additives — predating the current wave of interest in algae as novel whole foods.

Phycocyanin and astaxanthin are flagged with appropriate caution/hedging language, since I am not fully certain of their exact current E-number/Annex II status for food (as opposed to feed) use — I would rather flag this honestly than assert a specific E-number I'm not confident about.

The specific E-number assignments and current authorisation status for phycocyanin and astaxanthin as food colourants need a second check against the current Annex II of Regulation (EC) No 1333/2008 — I've deliberately hedged rather than guess precisely.

The EFSA re-evaluation programme reference (Regulation (EU) No 257/2010) — worth confirming this is still accurately described and that the re-evaluation timeline/status is current.