FD&C GREEN NO. 3, ALUMINUM LAKE

CAS: 977011-88-3 COLOR OR COLORING ADJUNCT

FD&C GREEN NO. 3, ALUMINUM LAKE is a pigment form of the synthetic food color FD&C Green No. 3 used to impart green color in foods and packaging contexts.

What It Is

FD&C GREEN NO. 3, ALUMINUM LAKE is a synthetic color or coloring adjunct derived from the parent dye commonly known as FD&C Green No. 3. This additive exists as an aluminum lake pigment, a form in which the soluble dye molecule is adsorbed onto an inert substrate such as aluminum hydroxide to produce an insoluble colorant. Aluminum lakes are widely used in food formulation when a water-insoluble tint is desirable, for example in dry mixes or packaging that contacts dry foods. The primary purpose of this ingredient is to provide a green hue in various food matrices. While the CAS number 977011-88-3 uniquely identifies this aluminum lake form, the parent dye FD&C Green No. 3 itself is recognized in the United States as a certified color additive. FD&C Green No. 3 is part of the family of synthetic triphenylmethane dyes historically developed for use in foods, drugs, and cosmetics. As a lake, the colorant shares the identity of the parent dye but is chemically bound to an aluminum-based substrate, changing its solubility and dispersion characteristics compared to the free dye. Lakes such as FD&C GREEN NO. 3, ALUMINUM LAKE are distinct from soluble dyes: they offer stable dispersion and are used where moisture management and controlled color release are critical. They are often listed on ingredient labels by their established nomenclature when included in finished products. The term "lake" indicates a specific class of pigment that meets criteria for purity and performance as set by regulatory authorities. Because of its formulation as a lake, this additive functions differently than simple dye salts, especially in terms of how it interacts with food matrices and other ingredients. It is not typically used for flavoring or nutritional purposes; its technological role is purely visual, enhancing or imparting color in processed foods.

How It Is Made

The manufacturing of an aluminum lake color additive like FD&C GREEN NO. 3, ALUMINUM LAKE begins with the production of the parent dye, FD&C Green No. 3, which historically is synthesized by condensation and oxidation reactions of specific sulfonated aromatic intermediates. Once the water‑soluble dye is prepared and purified, it is processed further to form the lake pigment. This typically involves combining the soluble dye with aluminum hydroxide or similar metallic substrates under controlled conditions that allow the dye molecules to adsorb onto or chemically bind with the substrate. The result is a finely divided, water‑insoluble pigment that retains the coloring properties of the parent dye but in a form more suitable for applications requiring moisture‑stable coloration. Production of aluminum lakes is conducted under strict quality controls to ensure consistency in color strength, particle size, and purity. Typical quality specifications include limits on contaminants, heavy metals, and residual solvents. The transformation from dye to lake does not fundamentally alter the chromophore responsible for the green color, but it changes the functional properties, creating a pigment that does not readily dissolve in water. Manufacturers of color additives must comply with regulatory standards and current good manufacturing practices (cGMP) to ensure the product is safe for its intended use and meets stated specifications. The final lake product is generally a fine, free‑flowing powder that disperses uniformly in dry blends or fat‑based systems, giving formulators flexibility in achieving consistent color application.

Why It Is Used In Food

FD&C GREEN NO. 3, ALUMINUM LAKE is used in foods primarily to impart or enhance green color in a controlled and stable manner. Color is a critical aspect of consumer perception; it influences expectations of flavor, quality, and freshness. Manufacturers add colorants such as this lake pigment to offset natural color loss that might occur due to processing, storage, or exposure to light. Because the aluminum lake form is insoluble, it is particularly useful in dry mixes, confections, coatings, and other products where a dispersed pigment is preferable to a soluble dye. This property can improve color stability and prevent unintended migration of color within a product or packaging. In formulation practice, the choice between a soluble dye and its lake counterpart depends on the food system. Lakes are often selected for foods with low moisture content or complex matrices where soluble dyes might not provide consistent visual effects. FD&C GREEN NO. 3, ALUMINUM LAKE allows product developers to achieve a desired shade and intensity without compromising texture or stability. It is used in a wide range of processed foods, from baked goods to confectionery, where vivid and durable color is part of the product identity. While aesthetic in function, the use of colorants like this is also tied to brand consistency: consumers expect similar appearance from batch to batch, and lakes help deliver that repeatability.

Adi Example Calculation

To illustrate how an ADI might be used in a regulatory context, consider a hypothetical example. Suppose the ADI for FD&C Green No. 3 (as evaluated by JECFA) upper bound is defined in scientific evaluations. For a person weighing 70 kilograms (about 154 pounds), the ADI would be calculated by multiplying the body weight by the ADI value. If the upper bound of the ADI range were known, this multiplication would yield a daily intake limit in milligrams that represents the maximum safe exposure over a lifetime. Such calculations help regulatory authorities and food scientists estimate safety margins for actual dietary exposures. These hypothetical examples serve to illustrate the mechanics of ADI application rather than specific intake recommendations for individuals.

Safety And Health Research

Regulatory safety evaluations focus on both the intrinsic properties of the additive and expected levels of exposure from food consumption. The parent dye FD&C Green No. 3, also known as Fast Green FCF, has been evaluated by international expert bodies such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA), which examined available toxicological data to determine safe levels of intake. Such evaluations consider endpoints like general toxicity, potential for genotoxicity, and chronic exposure studies. Based on these comprehensive data reviews, regulators establish benchmarks like acceptable daily intake ranges that represent levels of exposure not associated with adverse health effects when consumed over a lifetime. These quantitative assessments help inform both national regulations and international guidelines. It is important to note that the aluminum lake form itself is typically evaluated within the context of the parent dye because the chromophore responsible for color remains the same, even though its solubility and dispersion properties differ. Safety research on color additives also encompasses studies of absorption, distribution, metabolism, and excretion, with particular attention on whether the bound form in a lake alters these dynamics. Current scientific literature and regulatory evaluations do not indicate unique hazards associated with the aluminum lake compared to the parent dye beyond those already considered in comprehensive safety assessments. Nonetheless, ongoing monitoring and research help ensure that any new data on long‑term or high‑intake exposures are considered in regulatory decision‑making. As with all additives, safety conclusions are drawn from established toxicological methods and current data rather than anecdotal or speculative sources.

Regulatory Status Worldwide

In the United States, color additives used in foods must be either listed in the Code of Federal Regulations under specific sections or determined safe through a petition process. FD&C Green No. 3 itself, the parent dye from which the aluminum lake is derived, is permanently listed as a certifiable color additive subject to batch certification by the U.S. Food and Drug Administration under the color additive regulations. The lake form is included in the broader set of authorized derivatives that may be used under defined conditions, such as those found in 21 CFR Part 176.180 for indirect food additive use. This regulatory framework ensures that any use in contact with food packaging or direct food color applications meets safety and purity standards enforced by the FDA. The designation in 21 CFR 176.180 identifies this substance within the indirect food additives category when used in certain food contact applications, such as paper and paperboard components that contact dry food. The broader FD&C Green No. 3 regulations establish requirements for certification, permitted uses, and labeling when used in foods, drugs, and cosmetics. Outside the United States, regulatory acceptance varies. For example, the parent dye FD&C Green No. 3 is not authorized for use as a food colorant in the European Union, where synthetic lakes of this dye are similarly restricted. Regulatory bodies in other jurisdictions may evaluate such colorants based on local food additive lists and safety assessments. At the international level, bodies such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) have evaluated FD&C Green No. 3 (as Fast Green FCF) and established acceptable daily intake parameters for the parent dye, though the application to specific lake forms depends on national implementation of these evaluations. Manufacturers and food formulators must therefore consult both national food additive lists and specific regulatory references when determining permissible uses of this aluminum lake in foods.

Taste And Functional Properties

As a colorant, FD&C GREEN NO. 3, ALUMINUM LAKE does not substantially impart taste or nutritional value to foods. Its primary contribution is visual. In terms of sensory properties, the aluminum lake form is largely neutral: it does not dissolve readily in water and therefore does not interact significantly with flavor compounds. From a functional standpoint, its behavior in a food matrix is determined by its particle size and dispersion rather than flavor profile. Lake pigments tend to be stable in dry or emulsified systems, resisting migration and bleed that could otherwise affect product appearance. The physical properties of the lake make it suitable for applications where moisture control is essential. Because it is water‑insoluble, it distributes evenly without leaching color into adjacent phases. This can be advantageous in products like powdered drink mixes, coatings, or dry blends where localized concentration of color could lead to visual inconsistencies. In addition, the aluminum substrate can contribute to improved suspension and reduced settling compared to soluble dyes. While the human palate generally does not detect any flavor contribution from such colorants at typical use levels, product developers must ensure that the inclusion of a lake pigment does not affect other functional properties such as texture, moisture retention, or stability of sensitive ingredients.

Acceptable Daily Intake Explained

An acceptable daily intake (ADI) is a regulatory benchmark established by scientific bodies like JECFA that reflects the amount of a specific substance that can be consumed every day over a lifetime without appreciable health risk. It is typically expressed in milligrams of the additive per kilogram of body weight per day. The ADI incorporates safety margins based on animal studies and other toxicological data to ensure that even sensitive populations are protected. For FD&C Green No. 3 (the parent dye of the aluminum lake), JECFA has reviewed extensive evidence and expressed an ADI range that represents the upper bound of safe exposure based on the highest no‑observed‑adverse‑effect levels and appropriate uncertainty factors. This benchmark helps regulators and manufacturers assess whether typical dietary exposures to the additive fall well below levels of concern. While the ADI is a useful tool in regulatory risk assessment, it is not a target for consumption; it is a safety ceiling. Actual exposure from foods is generally far lower than the ADI for most approved food additives. ADIs are derived from comprehensive evaluations of toxicology studies that include chronic feeding experiments and, where available, human data. For color additives like FD&C Green No. 3 derivatives, this process ensures that any colorant permitted in food meets rigorous safety criteria. Acceptable daily intake values are updated as new scientific data emerge, though significant changes occur only when new, robust evidence warrants reevaluation.

Comparison With Similar Additives

FD&C GREEN NO. 3, ALUMINUM LAKE is one member of the broader class of synthetic color additives used in food. Other lakes derived from FD&C dyes, such as FD&C Red No. 40 Lake or FD&C Yellow No. 5 Lake, share similar roles in product coloration where insoluble pigment dispersion is needed. Compared to soluble dyes like the parent disodium salts, aluminum lakes offer enhanced stability in certain matrices, making them preferable in dry or low‑moisture products. In contrast, soluble dyes are often chosen for aqueous systems like beverages where quick dissolution and uniform color release are desired. The choice between lakes and soluble forms involves consideration of product formulation, desired visual effects, and processing conditions. Lake pigments also differ from natural colorants such as chlorophyll derivatives or beta‑carotene, which originate from plant sources and may impart hue alongside other compounds that can affect flavor or nutritional labeling. Synthetic lakes are engineered for color consistency and stability, whereas natural colorants may vary with source and extraction method. Across these categories, regulatory acceptance, functional performance, and consumer expectations shape how each colorant type is used in modern food production.

Common Food Applications Narrative

FD&C GREEN NO. 3, ALUMINUM LAKE finds application across a broad spectrum of processed foods where color plays an important role in consumer appeal. In confectionery, manufacturers may include this pigment in hard candies, sugar coatings, or decorative elements on desserts to achieve consistent green hues that are stable over shelf life. Its insoluble nature makes it suitable for decorative finishes that must resist smearing or bleeding when touched or exposed to humidity. In baked goods and icings, the lake can be blended into dry mixes or frostings to deliver uniform color without affecting texture, allowing for products that visually meet expectations for themed or seasonal items. Other applications include snack coatings and dry seasoning blends, where the visual impact of color contributes to product identity. In products like trail mixes or flavored nuts, color can signal flavor variety and enhance shelf presence. Similarly, in dietary supplements or powdered drink mixes, colored tablets or powders use lake pigments to differentiate formulas or flavors. While lakes like FD&C GREEN NO. 3, ALUMINUM LAKE are not typically used in high‑moisture beverages due to their insolubility, they are well suited to systems where dispersion stability is key. Across these applications, formulators rely on the controlled particle characteristics of the lake to deliver consistent, long‑lasting color that aligns with consumer expectations and product design goals.

Safety & Regulations

FDA

  • Notes: FDA listing in 176.180 is for indirect food additive use; parent dye regulation exists at 21 CFR Part 74 but specific direct food use authorization of this lake form is unclear from d sources.
  • Regulation: 21 CFR 176.180

EFSA

  • Notes: EFSA-specific evaluation of this aluminum lake form not found in d regulatory sources.

JECFA

  • Year: 2017
  • Notes: ADI range refers to parent dye Fast Green FCF evaluated by JECFA; applicability to this specific lake form is inferred.
  • Ins Number: 143
  • Adi Display: 0-25 mg per kg body weight

Sources

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