FD&C BLUE NO. 2, CALCIUM LAKE

CAS: 977011-14-5 COLOR OR COLORING ADJUNCT

FD&C Blue No. 2, Calcium Lake is a lake form of the synthetic blue food color used to add or adjust color in foods and food packaging. It appears in FDA inventories as a coloring adjunct under indirect food additive regulation 21 CFR 176.180. It is an insoluble form of a dye related to indigo carmine.

What It Is

FD&C Blue No. 2, Calcium Lake is a synthetic color additive used to impart a blue hue or adjust color in food products and food contact materials. It is a "lake" form of the dye associated with the Blue No. 2 family, where the soluble coloring matter is bound to an inert substrate such as calcium salts to create an insoluble material suitable for use in dry mixes or coatings. This form is related to the indigo carmine class of dyes but specifically configured as a calcium lake version, which changes its physical properties compared with the soluble disodium form commonly referenced as Indigo Carmine. Food additive inventories list FD&C Blue No. 2, Calcium Lake alongside its synonyms, including FD&C BLUE NO. 2-CALCIUM LAKE, INDIGOTINE-CALCIUM LAKE, and INDIGO CARMINE-CALCIUM LAKE, each indicating the same underlying color chemistry. Its technical function is categorized as a color or coloring adjunct, which means it is included to provide or adjust the visual appearance of a food item rather than for flavoring or nutritional purposes. In the context of food regulation, the term "lake" refers to the specific preparation of a coloring agent with an insoluble carrier, such as calcium, which allows the dye to be incorporated into food products where water solubility may not be desirable. The use of FD&C Blue No. 2, Calcium Lake is governed by regulatory frameworks that ensure that the additive meets purity and identity specifications, and its inclusion in any food product or contact material must align with appropriate good manufacturing practice and relevant laws. This form of the additive differs from the more soluble disodium form of FD&C Blue No. 2, which is used directly in food coloring applications where water solubility is required.

How It Is Made

The manufacturing process for FD&C Blue No. 2, Calcium Lake involves preparing the basic dye chromophore, then combining it with a calcium salt under controlled conditions to form the lake pigment. In general terms, color lakes are produced by reacting the dye or coloring matter with metal salts such as calcium, aluminum, or other polyvalent ions to precipitate an insoluble pigment. The process begins with the formation of the core dye structure, often derived from an aromatic compound like indigo or a related intermediate. For the Blue No. 2 family, the base colorant is typically generated through chemical reactions that produce the chromophoric system responsible for the blue hue. The soluble dye is then mixed with a suitable inorganic substrate, in this case, calcium salts, resulting in a pigment that is insoluble in water but retains the color properties of the underlying dye. During production, manufacturers adhere to quality specifications that limit impurities and ensure consistent color strength and stability. While the specific proprietary details of industrial synthesis can vary by manufacturer, the overall approach centers on forming a stable lake pigment that is suitable for blending into dry food formulations, coatings, or food-contact substrates. It is important that manufacturing conditions, including pH, temperature, and reagent quality, are controlled to achieve reproducible color characteristics. The resulting FD&C Blue No. 2, Calcium Lake powder or granules are typically free flowing and suitable for inclusion in various food formulations or food contact components, consistent with regulatory and industry standards.

Why It Is Used In Food

FD&C Blue No. 2, Calcium Lake is used in food and related materials primarily to provide or adjust color. Visual appearance is a key aspect of consumer perception of food quality, and color additives like FD&C Blue No. 2, Calcium Lake play a role in ensuring consistent and appealing appearance. In processed foods where the base ingredients might lack vibrant color, or where a specific shade of blue is desired, color lakes can deliver the hue without adding moisture or solubility that might otherwise affect product texture or stability. The lake form is especially useful for dry mix products or coatings where water solubility is not beneficial, allowing manufacturers to introduce color without altering other sensory or functional attributes of the food. Color additives also help maintain uniform product appearance across batches, which supports both quality control and consumer expectations. By selecting an appropriate form of the colorant, such as the calcium lake form, formulators can tailor how the pigment interacts with other ingredients. FD&C Blue No. 2, Calcium Lake may be combined with other colors or ingredients to achieve complex shades or to correct variations in natural colors, giving food producers flexibility in product design. Its role as a color or coloring adjunct underscores the focus on aesthetics rather than taste or nutritional contribution, and its use follows good manufacturing practices and regulatory guidelines to ensure safety and consistency in the final food products.

Adi Example Calculation

To illustrate how an acceptable daily intake (ADI) is applied, consider a hypothetical person with a body weight of 70 kilograms. If the established ADI for a coloring agent family related to FD&C Blue No. 2 is expressed as an upper bound, then multiplying the ADI by body weight gives the maximum daily intake that aligns with regulatory guidance. In this example, multiplying 70 kilograms by the ADI upper bound provides a theoretical daily intake figure for that person. This illustrative calculation helps show how regulators translate an ADI into a context that relates to consumer exposure, though actual intake from foods depends on how often and in what quantities products containing the additive are consumed. The calculation is purely illustrative and not a personal recommendation.

Safety And Health Research

Regulatory bodies evaluate color additives like the class associated with FD&C Blue No. 2, including their lake forms, by reviewing toxicological and exposure data to determine safety in food applications. For the underlying dye Indigotine or Indigo Carmine (INS 132), evaluations by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) have concluded that there is no need to revise the previously established acceptable daily intake range after considering available studies and dietary exposure estimates. JECFA’s assessment provides context for safety considerations related to these coloring agents, indicating that, at typical exposure levels, dietary intake remains below conservative safety thresholds identified by expert review. Such evaluations encompass a range of toxicological endpoints to ensure that color additives meet health-based guidance levels. In the European Union, scientific opinions by the European Food Safety Authority (EFSA) have re-evaluated the safety of Indigo Carmine (E 132) and confirmed existing acceptable intake levels while recommending updates to technical specifications, such as limits on certain elements. These assessments consider animal studies, potential impurities, and the manufacturing context of the additive, helping ensure that regulatory decisions reflect current scientific understanding. Safety research focuses on identifying any health concerns at realistic use levels rather than asserting physiological effects, and both JECFA and EFSA conclude that, when used appropriately, the dye class does not raise safety concerns for consumers in approved applications.

Regulatory Status Worldwide

In the United States, FD&C Blue No. 2 as a class of color additive is listed in Title 21 of the Code of Federal Regulations (21 CFR) Part 74 and subject to certification, which means that batches must be approved by the U.S. Food and Drug Administration (FDA) and conform to specifications before use in foods. The specific reference for FD&C Blue No. 2 in the CFR is Section 74.102, which outlines identity, specifications, and use conditions for the color additive, including restrictions that it be used in amounts consistent with good manufacturing practice and that it not be used in foods with established standards of identity unless authorized. While Section 74.102 refers to the soluble form, related lake forms such as calcium lakes fall under parallel regulatory frameworks and indirect additive citations like 21 CFR 176.180 when formulated for specific food contact applications. FDA labeling and certification requirements ensure that color additives meet quality and safety benchmarks before incorporation into food products. Internationally, similar regulatory evaluations occur through organizations like the Joint FAO/WHO Expert Committee on Food Additives (JECFA), which has assessed the base dye chemistry related to Indigo Carmine and established an acceptable daily intake range based on available safety data, and assessments by bodies such as the European Food Safety Authority (EFSA), which has reviewed the safety of Indigo Carmine (E 132) as a food additive. These evaluations consider toxicological data and typical dietary exposures and form part of global regulatory considerations, although specific lake forms may be addressed in national or regional legislation. Regulatory guidance emphasizes that use levels and product contexts align with good manufacturing practice and applicable food additive regulations.

Taste And Functional Properties

FD&C Blue No. 2, Calcium Lake contributes primarily visual impact rather than taste, as color lakes are formulated to provide pigment without dissolving or functioning as a flavor component. Sensory perceptions related to taste are typically minimal with color lakes, and they are generally considered to be neutral in flavor when incorporated into food matrices at typical usage levels. Because the calcium lake form is insoluble, it behaves differently than soluble dyes; it is more suitable for dry or nonaqueous food applications where color delivery without increased solubility is desirable. This property can be particularly advantageous in dry mixes, coatings, or encapsulated formulations where the additive must be suspended uniformly without altering the moisture balance. Functionally, FD&C Blue No. 2, Calcium Lake exhibits lightfastness and color stability when incorporated into appropriate food applications. As with other lake pigments, stability to heat and pH can vary with formulation and processing conditions, but the lake form itself supports uniform distribution in product matrices. It withstands typical food processing and storage environments when incorporated according to good manufacturing practice, helping maintain consistent appearance over shelf life. While it does not contribute to taste or texture, the physical properties of lake pigments can influence visual quality and product perception, making them valuable tools for formulators seeking specific aesthetic outcomes.

Acceptable Daily Intake Explained

An acceptable daily intake (ADI) is a health-based reference value established by expert panels, such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA), and represents an estimate of the amount of a substance in food that can be consumed daily over a lifetime without appreciable health risk. For the base dye chemistry associated with FD&C Blue No. 2 and its related substances, JECFA has confirmed an ADI range that reflects conservative safety factors and extensive evaluation of toxicological data. The ADI is not a recommended level of intake but a benchmark used by regulators to assess whether typical dietary exposure from food additives remains within a range deemed acceptable based on scientific evidence. Exposure assessments consider consumption patterns, additive use levels, and population groups to ensure that the intake of a coloring agent remains within established safety limits.

Comparison With Similar Additives

FD&C Blue No. 2, Calcium Lake belongs to a broader category of synthetic color additives used to impart blue hues in foods. A closely related additive is FD&C Blue No. 1 (Brilliant Blue FCF), which is another blue dye permitted in foods and regulated in similar ways but with distinct chemical structure and regulatory listings. While both provide blue color, they differ in chemical composition, spectral properties, and regulatory references. Another comparison is with natural colorants like spirulina extract or anthocyanins, which provide blue or purple tones derived from botanical sources. These natural alternatives vary widely in stability and cost compared with synthetic lakes. Other lake forms, such as aluminum lakes of red or yellow dyes, serve similar functional roles in dry applications but differ in hue and physical properties. Across these examples, formulators choose specific colorants based on desired shade, solubility, and regulatory status. Color lakes, including FD&C Blue No. 2, Calcium Lake, offer stable, insoluble pigments that integrate well into specific product types, whereas soluble dyes are selected where water solubility supports homogeneous color distribution.

Common Food Applications Narrative

FD&C Blue No. 2, Calcium Lake finds use in a range of food-related applications where a blue hue or consistent color profile is desired. Its inclusion is particularly relevant for dry and low-moisture formulations where a soluble dye might adversely affect texture or processing behavior. For example, in confectionery and dry baking mixes, lake pigments provide a stable, vibrant color that integrates well with other dry ingredients, contributing to the final product's visual appeal. In coatings and decorative applications, such as frostings or sugar work, the calcium lake form delivers consistent color depth without dissolving into the surrounding medium, which supports controlled design and presentation. Processed foods that include color lakes often span categories like snack products, cereals, powdered beverages, and toppings, where color consistency is an important aspect of consumer experience. Food packaging components that come in direct contact with dry food, such as paper or board materials, may also incorporate FD&C Blue No. 2, Calcium Lake to signal product attributes or support brand recognition. Across applications, the use of color lakes aligns with regulatory allowances and good manufacturing practices, ensuring that the visual qualities they provide help meet both industrial formulation goals and consumer expectations.

Safety & Regulations

FDA

  • Approved: True
  • Regulation: 21 CFR 176.180

EFSA

  • Notes: EFSA evaluations exist for Indigo Carmine but specific numeric ADI not directly d for this lake form.
  • E Number: 132

JECFA

  • Year: 2018
  • Ins Number: 132
  • Adi Display: 0-5 mg/kg bw
  • Adi Mg Per Kg: 5

Sources

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