Blue 1 Food Dye: Is It Safe? Uses, Labels & Evidence

Blue 1 (also written Blue #1, FD&C Blue No. 1, or brilliant blue FCF) is a synthetic, petroleum-based dye that the FDA still allows in US food, from blue raspberry candy to sports drinks and cereal. Regulators in the US and Europe consider it safe at approved levels, and it isn't one of the dyes behind the EU's hyperactivity warning. It may still leave US shelves soon: the FDA has asked manufacturers to remove it along with five other petroleum-based dyes, and now targets the end of 2027.

To check a package without reading the fine print, scan it with Osana: it flags Blue 1 and other synthetic dyes in seconds.

Key takeaways

• Blue 1, Blue #1, FD&C Blue No. 1, brilliant blue FCF and E133 are all names for the same synthetic dye.
• It often hides in green and purple foods, blended with Yellow 5, Yellow 6 or Red 40.
• The FDA permits it at approved levels, and EFSA set an acceptable daily intake of 6 mg per kg of body weight per day in its 2010 review.
• Removal is voluntary and targeted for the end of 2027, and products without certified dyes can now say "no artificial colors."

What is Blue 1 (Blue #1) food dye?

Blue 1 is a synthetic color additive that gives food a bright, vivid blue. The FDA lists it as FD&C Blue No. 1 under 21 CFR 74.101, and every production batch has to be certified by the agency before it can go into food. That batch check is why Blue 1 belongs to the group called "certified colors."

Color additives don't go through the GRAS pathway that covers many food ingredients. They need FDA approval before they reach the market, which is a stricter route.

The many names cause most of the confusion. "Blue 1," "Blue #1" and "FD&C Blue No. 1" are the US label versions. Europe uses E133, and cosmetic ingredient lists sometimes show the color index number CI 42090.

Blue 1 at a glance

Where Blue 1 hides: blue, green and purple foods

Blue 1 shows up in plenty of foods that don't look blue. Manufacturers blend it with other certified dyes to build new shades, so the color of a product won't always tell you what's inside.

Here's how the most common blends work:

• Green foods, like lime candy, green frosting or some sports drinks, often pair Blue 1 with Yellow 5 or Yellow 6. That's why you'll so often see Blue 1 and Yellow 6 side by side on a label.
• Purple foods, like grape-flavored treats or purple cupcake frosting, usually combine Blue 1 with Red 40.
• Bright blue foods, like blue raspberry slushies and gummies, may use Blue 1 alone or with Blue 2.

The categories to check first are candy and gummies, colorful kids' cereals, sports drinks, store-bought frosting and sprinkles, gelatin desserts, and some flavored chips. If you're mostly shopping for children, our guide to artificial food dyes in kids snacks covers the full lineup of dyes, not just Blue 1.

Is Blue 1 bad for you? What the evidence says

Current evidence doesn't show that Blue 1 harms most people at the amounts found in food. The FDA permits it at approved levels, and the European Food Safety Authority reached a similar conclusion when it reevaluated the dye in its 2010 scientific opinion on Brilliant Blue FCF. The open questions are narrower than many headlines suggest.

The hyperactivity study didn't test Blue 1

The research most people have in mind is a 2007 study published in The Lancet. It found that mixes of artificial food colors, given along with the preservative sodium benzoate, were linked to increased hyperactivity in some children.

Blue 1 wasn't among the dyes tested. EU rules later required a warning label on foods containing the six dyes from that study, and Blue 1 doesn't carry it. There's no strong standalone evidence linking Blue 1 alone to hyperactivity.

How much is too much: EFSA's limit

In its 2010 opinion, EFSA set an acceptable daily intake (ADI) for E133 of 6 mg per kg of body weight per day, lower than the limit used before. An ADI is the amount you could eat every day over a lifetime without appreciable risk, and it already includes a wide safety margin.

EFSA's exposure estimates gave a mixed picture for kids. A conservative estimate suggested the highest-consuming children could go above the ADI, while a refined estimate based on actual use levels kept them below it.

Allergy and sensitivity

True allergic reactions to Blue 1 appear to be rare. They show up mainly as individual case reports rather than a broad pattern. If you or your child seem to react to brightly colored foods, a doctor or allergist can help you figure out whether a dye is the trigger.

So, should you avoid it?

The honest answer: current evidence doesn't support calling Blue 1 dangerous for most people at typical intake. Still, if you're shopping for young kids, managing a sensitivity, or simply want fewer synthetic dyes in your cart, choosing products without them is a reasonable and very doable goal.

Blue 1 in the EU and UK: E133 explained

Blue 1 is legal in both the EU and the UK, where it appears on labels as E133. It's a common myth that Europe bans it. What differs is the labeling.

EU rules require foods containing six specific dyes to say they "may have an adverse effect on activity and attention in children." That list includes Tartrazine (E102) and Sunset Yellow (E110), the European names for Yellow 5 and Yellow 6. E133 isn't on it, so a European candy colored only with Blue 1 carries no such warning.

The UK still permits E133, under food additive rules carried over from EU law after Brexit.

Blue 1 FDA status: the end-of-2027 target

Blue 1 is still approved in the US, but the FDA wants it out of the food supply. On April 22, 2025, HHS and the FDA announced a plan to phase out petroleum-based synthetic dyes, naming Blue 1 along with Red 40, Yellow 5, Yellow 6, Blue 2 and Green 3.

The phase-out is voluntary for food companies, and the FDA now targets the end of 2027. The agency is tracking company pledges to reformulate, but no federal rule has revoked Blue 1's listing.

That's different from Red Dye 3. The FDA revoked Red No. 3's food authorization, and manufacturers have until January 15, 2027 to comply. The agency also revoked Orange B in July 2026 and has proposed revoking Citrus Red No. 2.

States are moving too. Several, including California, have restricted Blue 1 in school food. For the bigger picture, see our overview of US food additives under FDA review in 2026.

Natural blues replacing Blue 1

As brands reformulate, you'll see new names in place of Blue 1. The FDA has approved several plant- and algae-based blue colors, including galdieria extract blue, gardenia blue and butterfly pea flower extract. They appear on the ingredient list under their own names, not as a numbered dye.

A newer label rule helps too. Since February 5, 2026, the FDA allows "no artificial colors" claims on products that don't contain certified FD&C dyes, even if they use natural colorings. That claim is a useful shortcut when you're scanning a crowded shelf.

How to spot Blue 1 on a label

A few habits make Blue 1 easy to spot on your next grocery run:

1. Read the full ingredient list, not just the front of the pack. Claims like "made with real fruit" don't tell you whether synthetic dyes are present.
2. Look near the end of the list. Colors are usually listed toward the bottom of the ingredient panel.
3. Check green and purple products twice. Blue 1 is often one half of a blend.
4. Don't assume store brands are different. Store-brand versions often use the same dyes as the name brand, so check them too.

For a step-by-step approach to the rest of the panel, see how to read food ingredient labels.

The bottom line

Blue 1 is one of the most common synthetic dyes in US packaged food, especially in products aimed at kids. Regulators consider it safe at approved levels, but the FDA is steering companies away from it by the end of 2027, and natural blues are starting to replace it. Reading the ingredient list, especially on green, blue and purple foods, is the most reliable way to know what you're buying. If you'd like a faster check in the aisle, the Osana app can scan a barcode and flag Blue 1 and other certified dyes in seconds.

For every certified color side by side, with its E number and FDA status, see our list of food dyes.

Frequently asked questions

Is Blue 1 legal in the EU and UK?

Yes. Blue 1 is permitted in both as E133. Unlike Tartrazine (Yellow 5) and Sunset Yellow (Yellow 6), it doesn't require the EU warning about activity and attention in children.

Can you be allergic to Blue 1?

Reactions appear to be rare and are mostly described in individual case reports. If you suspect a dye sensitivity in yourself or your child, talk with a doctor or allergist before cutting foods on your own.

Will Blue 1 be banned in the US?

Not by federal rule so far. The FDA has asked companies to voluntarily remove Blue 1 and five other petroleum-based dyes, and now targets the end of 2027. Several states, including California, have already restricted it in school food.

Is Blue #1 the same as Blue 1 and brilliant blue?

Yes. Blue #1, Blue 1, FD&C Blue No. 1, brilliant blue FCF and E133 all refer to the same synthetic dye. On US labels, it's most often listed as "Blue 1."