FD&C Blue No. 2 (Indigotine): FDA Phase-Out, State Bans & Compliance Guide

What Is FD&C Blue No. 2?

FD&C Blue No. 2, also known as Indigotine or Indigo Carmine, is a synthetic indigo dye authorized by the U.S. Food and Drug Administration as a certified color additive for use in foods, drugs, and cosmetics. It is the disodium salt of 2-(1,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-2,3-dihydro-3-oxo-1H-indole-5-sulfonic acid — a sulfonated derivative of indigo, one of the oldest known dyes in human history.

Property	Value
CAS Number	860-22-0
UNII	D3741U8K7L
E Number (EU)	E 132
CI Number	Acid Blue 74 (CI 73015)
Molecular Formula	C₁₆H₈N₂Na₂O₈S₂
Molecular Weight	466.35 g/mol

In its pure form, FD&C Blue No. 2 is a blue-brown to red-brown powder that dissolves in water to produce a blue solution at neutral pH, shifting to blue-violet in acidic conditions and green to yellow-green in basic conditions. It is notably the least soluble of all certified food color additives, with a solubility of just 1.6 g per 100 mL of water at 25°C.

While its parent compound indigo is derived from plants (historically Indigofera tinctoria), the FD&C-certified form is synthesized from petroleum-based precursors — a distinction at the center of the current regulatory debate. The dye produces blue hues in confectionery, baked goods, cereals, snack foods, ice cream, and beverages. It is also widely used in pet food.

Among the six petroleum-based dyes targeted by the FDA's 2025 voluntary phase-out initiative, Blue No. 2 occupies a distinctive position: it is the least commonly used in food manufacturing. FD&C Blue No. 1 (Brilliant Blue FCF) dominates the blue food color market due to superior stability and brightness, making Blue No. 2 a relatively minor player in the reformulation challenge facing the industry. However, its widespread use in pharmaceutical tablets, capsules, and surgical sutures complicates any blanket removal strategy.

FDA Regulatory Status

Current Authorization

FD&C Blue No. 2 is currently listed as a certified color additive under multiple sections of the Code of Federal Regulations:

• 21 CFR 74.102 — Authorizes use in foods generally, including dietary supplements, subject to batch certification
• 21 CFR 74.1102 — Authorizes use in drugs intended for ingestion, in amounts consistent with current good manufacturing practice (cGMP)
• 21 CFR 74.2102 — Authorizes use in externally applied cosmetics
• 21 CFR 74.3102 — Authorizes use in contact-area medical devices, specifically surgical sutures

All batches must be submitted to the FDA for analysis and certification before the color additive can be used in any FDA-regulated product sold in the United States.

The April 22, 2025 Announcement

On April 22, 2025, HHS Secretary Robert F. Kennedy Jr. and FDA Commissioner Dr. Marty Makary jointly announced a national initiative to eliminate petroleum-based synthetic dyes from the American food supply. The announcement targeted six certified color additives for voluntary phase-out:

1. FD&C Red No. 40 (Allura Red)
2. FD&C Yellow No. 5 (Tartrazine)
3. FD&C Yellow No. 6 (Sunset Yellow)
4. FD&C Blue No. 1 (Brilliant Blue)
5. FD&C Blue No. 2 (Indigotine)
6. FD&C Green No. 3 (Fast Green)

The target date for industry-wide elimination is the end of 2027.

Separately, the FDA initiated formal revocation proceedings against Citrus Red No. 2 and Orange B — two rarely used dyes being removed through rulemaking. Orange B has not been certified for use since 1978.

What "Voluntary" Means

The April 2025 announcement is not a ban. During the press conference, Secretary Kennedy clarified that the phase-out depends on an "understanding" with the food and beverage industry — not a formal rulemaking action.

• No proposed rule to revoke the listing of FD&C Blue No. 2 under 21 CFR 74.102 has been published in the Federal Register
• No notice of proposed rulemaking (NPRM) is pending for any of the six targeted dyes
• The FDA cannot revoke a color additive listing without going through formal rulemaking under the Federal Food, Drug, and Cosmetic Act
• The FDA is tracking voluntary industry commitments through a public pledge tracker on its website

The voluntary nature of the phase-out creates a two-track regulatory environment: companies face no immediate federal legal obligation to reformulate, but they face growing market pressure from institutional purchasers (school districts, hospital food services) operating under state-level mandates that are legally binding.

Natural Alternatives Approved

The FDA has simultaneously accelerated approval of natural blue color alternatives:

• Spirulina extract — Approved for broad food use (expanded in February 2026); limited heat stability
• Butterfly pea flower extract — Approved September 2021; excellent heat stability, good for beverages and frozen products
• Galdieria extract blue — Approved May 9, 2025; derived from red algae Galdieria sulphuraria
• Gardenia blue (Genipin blue) — Approved July 2025; strong acid stability, suitable for carbonated beverages and confectionery

Key Deadlines

Date	Event	Type
May 7, 2025	Utah HB 402 school food ban effective	State (mandatory)
August 1, 2025	West Virginia HB 2354 school meals ban effective	State (mandatory)
August 2026	Arizona HB 2164 school food ban effective (2026-27 school year)	State (mandatory)
July 1, 2027	Virginia SB 1289 school food ban effective	State (mandatory)
December 31, 2027	California AB 2316 school food ban effective; FDA voluntary phase-out target	State/Federal
January 1, 2028	West Virginia HB 2354 statewide retail ban effective	State (enjoined)

State-Level Bans

A wave of state legislation targeting synthetic food dyes has created a patchwork of binding legal obligations. As of March 2026, five states have enacted laws that specifically include FD&C Blue No. 2.

West Virginia — HB 2354 (Most Aggressive)

Signed: March 24, 2025, by Governor Patrick Morrisey

West Virginia enacted the broadest state-level food dye law in the country — the only one with a retail phase extending beyond school meals.

• Phase 1 — School meals (August 1, 2025): Bans Blue No. 2 (along with Red 3, Red 40, Yellow 5, Yellow 6, Blue 1, Green 3) from K-12 school meal programs. This phase is in effect.
• Phase 2 — Statewide retail (January 1, 2028): Bans the listed substances plus BHA and propylparaben from any food, drink, confectionery, or condiment distributed in West Virginia.

Preliminary Injunction (December 23, 2025): U.S. District Judge Irene Berger issued a preliminary injunction blocking enforcement of Phase 2 (the retail ban), finding HB 2354 unconstitutionally vague. The injunction does not affect Phase 1 (school meals), which remains in effect.

California — AB 2316 (First Enacted)

Signed: September 28, 2024, by Governor Gavin Newsom

The California School Food Safety Act was the first state law in the nation to ban synthetic food dyes in schools. It prohibits the sale or service of food containing Red 40, Yellow 5, Yellow 6, Blue 1, Blue 2, and Green 3 in public schools.

• Effective date: December 31, 2027

Virginia — SB 1289

Signed: March 21, 2025, by Governor Glenn Youngkin

Virginia's law passed both chambers unanimously, reflecting bipartisan alignment on school food safety.

• Effective date: July 1, 2027
• Scope: Public and secondary school meals, breakfast programs, and "competitive food"
• Banned dyes: Blue 1, Blue 2, Green 3, Red 3, Red 40, Yellow 5, Yellow 6

Utah — HB 402

Signed: 2025 legislative session, by Governor Spencer Cox

• Effective date: May 7, 2025
• Scope: Public schools; prohibits selling or serving food containing listed dyes
• Banned substances: Blue 1, Blue 2, Green 3, Red 3, Red 40, Yellow 5, Yellow 6, potassium bromate, propylparaben

Arizona — HB 2164

Signed: April 14, 2025, by Governor Katie Hobbs

• Effective date: Beginning of the 2026-2027 school year
• Scope: Schools participating in federally funded or assisted meal programs
• Banned substances (11 total): Blue 1, Blue 2, Green 3, Red 3, Red 40, Yellow 5, Yellow 6, potassium bromate, propylparaben, titanium dioxide, brominated vegetable oil

Additional State Activity

Over 140 food additive bills were introduced across 38 states during 2025. Companies operating nationally should assume that the school food channel will become a synthetic-dye-free zone within 2-3 years across most major states.

International Status

European Union — E 132

Indigotine is authorized as food additive E 132 in the European Union under Regulation (EC) No 1333/2008, subject to maximum permitted levels (MPLs) — stricter usage caps than the U.S., where the standard is "consistent with cGMP."

EFSA re-evaluated indigo carmine in 2014 and published a follow-up assessment in July 2023 (EFSA Journal 2023;21(7):8103). Key findings:

• ADI confirmed at 5 mg/kg body weight per day (for the disodium salt form meeting a minimum 85% purity specification)
• The Panel concluded that indigo carmine is poorly absorbed from the gastrointestinal tract and does not raise concern for genotoxicity
• No safety concern was identified at reported use levels and current MPLs

Important distinction on warning labels: FD&C Blue No. 2 / E 132 is not one of the "Southampton Six" dyes that require the EU mandatory warning label stating "may have an adverse effect on activity and attention in children." That warning applies only to Tartrazine (E 102), Quinoline Yellow (E 104), Sunset Yellow (E 110), Carmoisine (E 122), Ponceau 4R (E 124), and Allura Red (E 129). Blue No. 2 is exempt from this labeling requirement.

United Kingdom

Following Brexit, the UK retained E 132 authorization under retained EU law. No additional restrictions have been proposed.

JECFA (International)

JECFA established an ADI of 0-5 mg/kg bw/day in 1975, based on a long-term rat study showing inhibited growth at doses of 1,000 and 2,500 mg/kg bw/day, with a NOAEL of 500 mg/kg bw/day. JECFA's most recent review (73rd meeting, 2010) confirmed the ADI, finding no reason for revision.

Canada

Health Canada lists Indigotine (Indigo Carmine) as a permitted food color, allowing its use within specified limits. No phase-out or review has been announced.

Affected Product Categories

Food Products (Highest Impact)

Blue No. 2 appears in:

• Confectionery and candy — particularly products requiring darker blue, purple, or green hues (achieved by combining with Yellow 5 or Yellow 6)
• Baked goods — frostings, decorative icings, cake mixes
• Cereals and snack foods — colored cereal pieces, flavored chips
• Ice cream and frozen desserts — blue-tinted and purple-tinted varieties
• Beverages — limited use due to poor pH stability; more common in neutral-pH dairy-based drinks
• Pet food — a significant end market, as color is used to differentiate kibble flavors visually for purchasers

Dietary Supplements

Blue No. 2 is used in supplement capsule shells and tablet coatings for product differentiation and brand identity.

Drugs and Cosmetics

Blue No. 2 is authorized under 21 CFR 74.1102 for ingested drugs and 21 CFR 74.2102 for externally applied cosmetics. These uses are not addressed by the April 2025 voluntary phase-out. The dye's extensive use in tablet and capsule identification systems creates significant switching costs in the pharma sector.

Medical Devices

Under 21 CFR 74.3102, Blue No. 2 is authorized for use in surgical sutures, where color coding aids surgical teams. This use is unaffected by the food-focused phase-out.

What Companies Should Do

1. Audit Your Product Portfolio

Identify every SKU that contains FD&C Blue No. 2, either as a standalone colorant or as part of a color blend. Map each SKU to its distribution channels:

• Sold to school food programs in UT, WV, AZ, VA, or CA? — Compliance deadlines are binding and staggered. Utah and West Virginia school bans are already in effect.
• Sold at retail in West Virginia? — The January 2028 retail ban is currently enjoined, but the injunction could be lifted.
• National distribution? — Anticipate additional state-level school food bans.

2. Evaluate Natural Blue Alternatives

Alternative	FDA Status	Best For	Limitations
Spirulina extract	Approved (expanded Feb 2026)	Confectionery, frozen desserts, dry mixes	Poor heat stability
Butterfly pea flower extract	Approved (2021)	Beverages, frozen products, confectionery	Color shifts with pH
Galdieria extract blue	Approved (May 2025)	Beverages, candy, ice cream, yogurt, cereals	Newer to market; supply scaling
Gardenia blue (Genipin blue)	Approved (July 2025)	Carbonated beverages, acidic confectionery	Newest option; limited data

Because Blue No. 2 is already the least-used of the six targeted dyes, many manufacturers may find that their Blue No. 2 reformulation burden is lighter than their Red 40 or Yellow 5 burden.

3. Monitor the Regulatory Landscape

• Federal: Watch for any NPRM targeting the 21 CFR 74.102 listing. No such rule has been proposed as of March 2026.
• State: Track legislation in your distribution states. The pattern is clear: school bans first, broader retail bans later.
• International: Companies exporting to the EU should verify compliance with E 132 MPLs, which are more restrictive than U.S. cGMP standards.

4. Supply Chain Communication

Notify upstream suppliers and downstream customers of your reformulation timeline. Key institutional buyers — school food distributors, hospital group purchasing organizations, university dining services — are increasingly writing dye-free requirements into procurement contracts.

Regulatory Intelligence

Policy Canary tracks regulatory items linked to FD&C Blue No. 2 across enforcement actions, guidance documents, and Federal Register notices. Subscribe to receive alerts when new regulatory actions affect this substance.