Brilliant Blue FCF (Blue 1) (E133)

Brilliant Blue FCF (Blue 1) is the color the food industry lists as E133. In our table it is low risk: it takes 6 points off the additive subscore (about 2 of the 100).

What Blue 1 does to a score

A packaged food's additive subscore starts at 100 and loses points for each additive on the label; that subscore is a third of the final score. Blue 1 takes 6 points off the additive subscore (about 2 of the 100), and a child under 6 sees it one class higher again. Scan the pack in Sito and the score you get is the one for your own child's age, with this additive named in the reasons. How we score has the whole method.

What the sources found

Every classification in our table comes from the citations below, and nothing else. Each finding is our one-line summary of what the source concluded, with the source and reference beside it.

• EFSA 10.2903/j.efsa.2010.1853
  ADI reduced from 10 to 6 mg/kg bw/day; Tier-2 intake estimates above the ADI at the 95th percentile for children (Tier-3 refined estimates below the ADI).
• OEHHA (2021) synthetic food dyes / children neurobehavioral assessment
  Blue 1 is one of the seven dyes assessed. OEHHA's overall conclusion is that synthetic food dyes can impact neurobehavior in some children; its review of human studies suggests that synthetic food dyes are associated with adverse neurobehavioral effects, such as inattentiveness, hyperactivity and restlessness in sensitive children, and that some children are likely to be more adversely affected than others.
• US state law US-CA: AB 2316 ; US-WV: HB 2354 (school provisions in force 2025-08-01)
  Blue 1 banned from California public-school food from 2027-12-31 and already barred from WV school food.
• FDA Tracking Food Industry Pledges to Remove Petroleum Based Food Dyes (fda.gov)
  Blue 1 is in the voluntary industry phase-out FDA targets by end of 2027; it remains legally authorised in the meantime.

Why this class

A credible adverse or precautionary signal that stops short of every Moderate and High criterion: peer-reviewed adverse findings not yet reflected in regulatory status, an exposure exceedance confined to high-percentile or single-event estimates, or a precautionary regulatory step short of those criteria, a reduced ADI, a data limitation noted without an adverse conclusion, a narrowed or conditioned authorisation, or a child-focused assessment or school-food law that covers the additive as part of a class.

Our confidence in this row's classification is medium. Medium or low does not mean the evidence is weak; it means something about the row is still being pinned down, usually a regulatory status confirmed from one source rather than two.

Questions parents ask

Is Blue 1 (E133) safe for kids?

Low risk. In Sito it takes 6 points off the additive subscore (about 2 of the 100). It is flagged for young children, so for a child under 6 it moves up one class, to moderate risk: 15 points off the additive subscore. The finding we rely on: ADI reduced from 10 to 6 mg/kg bw/day; Tier-2 intake estimates above the ADI at the 95th percentile for children (Tier-3 refined estimates below the ADI) (EFSA, 10.2903/j.efsa.2010.1853).

What is E133?

E133 is the E number for Brilliant Blue FCF, a color. It is also called Blue 1. Open Food Facts tags it en:e133.

Next to it on the label

The E numbers either side of E133 in our table, then the closest colors by number.

• Red 3 (E127), high risk, flagged for young children
• Red 2G (E128), high risk
• Red 40 (E129), moderate risk, flagged for young children
• Patent Blue V (E131), low risk
• Blue 2 (E132), low risk, flagged for young children
• Chlorophylls and chlorophyllins (E140), no risk identified