FD&C GREEN NO. 3, CALCIUM LAKE

CAS: 977011-12-3 COLOR OR COLORING ADJUNCT

FD&C GREEN NO. 3, CALCIUM LAKE is a synthetic color additive form of Fast Green FCF used as a colorant component in specific indirect food contact applications.

What It Is

FD&C GREEN NO. 3, CALCIUM LAKE is a synthetic color additive derivative of the dye Fast Green FCF formulated as a calcium lake salt. A "lake" form generally refers to a pigment created by precipitating a soluble dye with certain metal salts, such as calcium, aluminum, or other polyvalent cations, to form an insoluble pigment. The calcium lake form is used in applications where a stable pigment is needed rather than a soluble dye. This ingredient carries the Chemical Abstracts Service number 977011-12-3 and is typically used in contexts where insoluble color carriers are advantageous. As a coloring adjunct, it is not used for flavor or nutritional impact but primarily to provide green tinting in certain regulated contexts.

How It Is Made

The production of FD&C GREEN NO. 3, CALCIUM LAKE generally involves chemical synthesis of the parent dye structure followed by precipitation with a calcium salt to create an insoluble pigment form. The parent dye Fast Green FCF is itself a synthetic triphenylmethane-based colorant, which is manufactured by organic synthesis that couples aromatic sulfonic acid derivatives into the characteristic dye core. Once the soluble dye is produced to required purity specifications, it is reacted with calcium salts under controlled pH and temperature to form a lake pigment. This lake form alters the physical properties of the dye, making it more suitable for certain applications where solubility in water is minimized. The manufacturing process must comply with good manufacturing practices and often follows guidance and purity specifications consistent with color additive manufacturing standards. Because this ingredient is not itself widely used outside of regulated applications, detailed industrial synthesis protocols beyond these general steps are proprietary to manufacturers.

Why It Is Used In Food

FD&C GREEN NO. 3, CALCIUM LAKE is used for its coloring properties. Pigment forms such as lakes offer stability in systems where water solubility of dyes could lead to migration or bleeding. In applications such as color in paper and paperboard that contact dry foods, the calcium lake form of the dye can be incorporated to provide a consistent green hue without dissolving into surrounding moisture. The technical function of the ingredient is to provide visual color signals that can enhance the appearance or aid in the identification of products. It is not used for taste, nutrition, or preservation. Use of lake pigments is common where formulation stability or specific regulatory allowances dictate their use over soluble dyes. Such additives are selected for compatibility with the matrix, stability under processing conditions, and adherence to applicable regulatory standards for intended uses.

Adi Example Calculation

To illustrate how an ADI might be applied, consider a hypothetical individual weighing 70 kilograms. If an international expert committee has established an ADI range with an upper bound of 25 milligrams per kilogram body weight per day for the parent dye class, the calculation would involve multiplying the body weight by this value. For a 70 kg person, the upper-bound ADI would be calculated as 70 times 25, equating to 1750 milligrams per day. This figure represents the maximum amount of the additive that could be ingested daily over a lifetime without appreciable health risk according to current scientific evaluations. It is illustrative only and does not imply typical intake levels, which are generally much lower. Actual exposure from indirect contact materials is usually minimal and well below such thresholds under authorized use conditions.

Safety And Health Research

Safety assessments of color additives consider toxicological data, exposure estimates, and effects on organ systems. The parent compound Fast Green FCF has been evaluated by international expert bodies such as JECFA, which reviewed long-term dietary studies in rats to determine a range of acceptable daily intake based on observed no-effect levels and conservative exposure assessments. Safety research for color additives generally includes studies on genotoxicity, carcinogenicity, reproductive and developmental toxicity, and metabolic fate. For lake forms like the calcium salt, the pigment’s insoluble nature often limits systemic absorption, and regulatory evaluations focus on ensuring minimal migration from contact materials or limited exposure. Toxicological studies typically involve controlled animal studies where different doses are administered to identify any adverse effects and determine thresholds for safe exposure. Expert committees synthesize this data to set intake recommendations or guidance values. Because the pigment form is used in indirect applications with limited direct food contact, safety considerations emphasize compliance with regulatory limits, manufacturing quality control, and evaluation of potential impurities. Historical data and international evaluations underpin regulatory decisions, but ongoing surveillance and research inform updates to safety profiles as new evidence becomes available.

Regulatory Status Worldwide

Regulatory status of FD&C GREEN NO. 3, CALCIUM LAKE varies by jurisdiction and by intended use. In the United States, this specific lake form is listed under 21 CFR 176.180, which pertains to components of paper and paperboard in contact with dry food, indicating authorized use under specified conditions in that context. The parent dye Fast Green FCF (FD&C Green No. 3) is a certified color additive in the U.S. under 21 CFR Part 74 for general coloring of foods, drugs, and cosmetics, subject to batch certification and good manufacturing practices, although the direct applicability of those color additive regulations to the calcium lake form differs based on intended use. In jurisdictions such as the European Union, Fast Green FCF itself (without specifying the lake form) is not permitted as a food color component, and analogous lake pigments are also generally not authorized for food use. JECFA, the Joint FAO/WHO Expert Committee on Food Additives, has evaluated Fast Green FCF in its chemical class and provided an acceptable daily intake range based on toxicological assessments. These evaluations inform international standards and Codex Alimentarius guidelines. Regulatory frameworks reflect differences in use conditions, such as direct food coloring versus indirect food contact materials, and incorporate safety evaluations by expert bodies to determine allowable contexts.

Taste And Functional Properties

FD&C GREEN NO. 3, CALCIUM LAKE does not contribute taste or aroma to products; its role is purely visual. As a lake pigment, the calcium form is essentially insoluble in water, which affects how it disperses in a formulation. Instead of dissolving, it stays as finely divided particles that impart color without solubility-dependent interactions. The pigment is relatively stable to light and processing conditions typical in paper and food contact applications but may fade under prolonged exposure to intense light or certain chemical environments. Because it is designed to be insoluble, it does not migrate significantly into contacting media, which can be a functional advantage in controlled applications. The green color it imparts is based on absorption of particular wavelengths of visible light, and the specific shade may vary depending on particle size and formulation context.

Acceptable Daily Intake Explained

An acceptable daily intake (ADI) is a health-based guidance value representing the amount of a substance that can be ingested daily over a lifetime without appreciable health risk, based on current scientific evidence. For synthetic colorants like Fast Green FCF, international expert panels such as JECFA review toxicological studies and exposure assessments to derive ADI ranges. These ranges are typically based on no-observed-adverse-effect levels from animal studies and incorporate safety factors to account for uncertainties when extrapolating to humans. It is important to understand that the ADI is a conservative estimate for regulatory purposes, not a recommended dietary target. Actual dietary exposure to color additives through food and indirect contact materials is generally a fraction of the ADI. The ADI helps regulatory agencies establish allowable use conditions and limits that ensure consumer safety. Because FD&C GREEN NO. 3, CALCIUM LAKE is used in specific contexts where direct food exposure is controlled, the ADI for the parent dye informs safety considerations for overall exposure to this class of compounds.

Comparison With Similar Additives

Color additives used in food and related materials include a range of synthetic dyes and their lake forms. For example, FD&C Blue No. 1 (Brilliant Blue FCF) and FD&C Yellow No. 5 (Tartrazine) are synthetic colorants that, like Fast Green FCF derivatives, are subject to regulatory evaluation and certification where permitted. Lake forms of these dyes are often used where insolubility or formulation stability is required, such as in coated tablets or printing inks for packaging. Compared with soluble dyes, lake pigments tend to stay within the matrix where they are applied rather than migrating into aqueous phases. Regulatory frameworks treat each color additive separately, with specific use conditions and safety evaluations. Some additives, such as natural carotenoid-based colors, offer alternative color solutions with different regulatory and safety considerations. In jurisdictions where certain synthetic colors are restricted or banned, manufacturers may turn to blends of approved colorants or natural pigments to achieve desired hues. The technical performance, stability, shade, and regulatory acceptance vary across these options, and formulating decisions must balance visual objectives with compliance and safety assessments.

Common Food Applications Narrative

In broad terms, color additives like FD&C GREEN NO. 3, CALCIUM LAKE are not incorporated for flavor or nutrition but to influence the appearance of materials with which foods interact. One regulated application is as a component in paper and paperboard that contacts dry food, where the pigment can be part of printing or surface coloration. In such contexts, the green hue can help differentiate packaging materials or printed information. Beyond paper contact materials, lake pigments may be formulated into other substrates where insoluble dyed particles provide a visual cue without transferring into food. Although the calcium lake form itself is not typically listed as a direct food ingredient in ingredient statements, its utility in color coding related materials can be part of a broader visual communication strategy in packaging and labeling. Because visual appeal and clear identification are important to manufacturers and consumers alike, approved color additives and their lake forms have a role in the overall food ecosystem. Use of color in food packaging and contact materials can influence consumer perception, brand recognition, and quality communication, even though the additive itself does not change the food’s sensory properties. Regulatory frameworks ensure these applications are limited to conditions and contexts that meet safety and compliance criteria, such as use in dry food contact applications rather than direct addition to diverse food matrices.

Safety & Regulations

FDA

  • Notes: This specific lake form appears in indirect food contact regulation 21 CFR 176.180; parent dye certification under 21 CFR Part 74 applies to the soluble dye but not directly to the lake form for all uses.

EFSA

  • Notes: EFSA authorization for FD&C Green No.3 or its lake form is not established in the EU; colorant restrictions in EU apply and Fast Green FCF is generally not permitted for food use.

JECFA

  • Year: 2017
  • Ins Number: 143
  • Adi Display: 0-25 mg/kg bw
  • Adi Mg Per Kg: 25

Sources

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