Calcium Carbonate

Calcium Carbonate:

Calcium carbonate is a chemical compound that has many industrial applications. It is used medicinally, and as a food additive.


Calcium carbonate is the main component in egg shells. It is also a main component in the shells of marine animals and snails.1 However, most of the calcium carbonate used industrially comes from mining. Even when used in pharmaceuticals or as a food additive, it is often produced from quarried marble.2

The chemical formula of calcium carbonate is CaCO3. It typically comes as a white solid, either crystals or powder. It is odorless, chalky, and flat. It can have a sweetish flavour.

Calcium carbonate is not soluble in water. However, it can be emulsified to disperse in water.

The E number of calcium carbonate is 170. This means that it is classified as a food colour, even thought it has many other uses.

Common Uses:

When used in food, it can:

  • Control acidity,
  • Act as a white food colour,
  • Act as a firming agent for vegetables,
  • Act as a nutrient for yeasts,
  • Add an additional source of calcium,

Calcium carbonate is a stable food coloring. It does not require any special processing to preserve its coloring properties.2 It can also be used as a food preservative and color retainer in organic fruits and other foods.

Many foods (especially soy milk and soy products) are calcium enriched. Calcium carbonate is often used as the calcium source.

It can also be a stabilizer, added mainly to dairy products.

There are a lot of uses of calcium carbonate. It can be found in almost all kinds of foods from dried fruits to canned sardines, also in frozen foods, cereals, aromatized beverages and processed meat and fish products.3

In some beer brewing operations, calcium carbonate is used as a nutrient for the yeast.

Health Issues / Side Effects:

Calcium carbonate can be potentially harmful only in concentrated solid form or in very concentrated solutions.

Otherwise, direct eye or skin contact with pure crystals or powder can produce irritation. Breathing crystals or powder can be irritating to the respiratory tract, and contact with concentrated solutions of calcium carbonate has a drying effect on skin.4


In 1861, a Belgian chemist named Ernest Solvay, invented a process for producing sodium carbonate (sometimes called soda ash). Sodium carbonate was coming into high demand at the time because it is used in glass making. Glass is made by melting silica sand, calcium carbonate and sodium carbonate together.

Solvay’s process basically takes limestone (CaCO3) and salt Brine (2 NaCl) to produce sodium carbonate (Na2CO3). The main by-product of the Solvay process is calcium chloride.


  1. Wikipedia
  2. DDW Color – Food Colouring Manufacturer
  3. Calcium Carbonate In-R-Food
  4. Oregon Department of Human Services
Posted in Colour, Food Additives, Ingredients

Ponceau 6R

Ponceau 6R

Ponceau 6R is a bright red synthetic dye used to colour food. The name comes the French word for poppy. It is part of a family of dyes called Ponceau dyes.

Other names include crystal scarlet, acid red 44, or C.I. 16250.


Ponceau dyes are azo dyes meaning they are formed when two hydrocarbon groups are joined by two nitrogen atoms. The molecular formula for Ponceau 6R is C20H12N2Na2O7S2.

Ponceau 6R, like all azo dyes, is produced from petroleum products.

The E number of Ponceau 6R is 126. Other dyes in the Ponceau family include:

Ponceau 2R
Ponceau 4R (E Number 124)
Ponceau S
Ponceau SX (E Number 125)

Common Uses:

It is not widely used, but can be found in cake mixes, fruit-flavoured fillings, and jelly crystals. It is approved for use in both the US and the EU.1

Besides its use as a food dye, ponceau 6R is commonly used when studying cells. It is used as a stain so that certain structures can more easily been seen under a microscope. It is closely related to amaranth, another red azo dye used for staining.

Health Issues / Side Effects:

Some studies on the safety of this colour were performed in 1974.2 These studies did not include detailed observations. They did not report any adverse effects except for the possibility of sensitivity reactions in people allergic to benzoates and aspirin.


  1. Analytical Standards for Food Color Additives (Sigma-Aldrich)
  2. International Programme on Chemical Safety (IPCS)
Posted in Colour, Food Additives, Ingredients, Uncategorized

Ponceau 4R

Ponceau 4R

Ponceau 4R is a bright red synthetic dye used to colour food. The name comes the French word for poppy. It is part of a family of dyes called Ponceau dyes.

Other names include Cochineal Red A, New Coccine, CI Food Red 7, or CI (1975) No. 16255.1


Ponceau dyes are azo dyes meaning they are formed when two hydrocarbon groups are joined by two nitrogen atoms. The molecular formula for Ponceau 4R is C20H11N2Na3O10S3.

Ponceau 4R, like all azo dyes, is produced from petroleum products.

The E number of Ponceau 4R is 124. Other dyes in the Ponceau family include:

Common Uses:

Ponceau 4R is currently not approved for use in the US or Canada. However, it is still commonly used in other parts of the world (including Europe).

It is used to colour a wide range of products; everything from candies to Chorizero sausage spices. In the US, imported products containing Ponceau 4R are recalled by the FDA.2

Health Issues / Side Effects:

In 2009, the European Food Safety Authority re-evaluated Ponceau-4R used as a food colouring.3 The panel concluded that:

  • There were no long term carcinogenic effects.
  • Combinations of artifical food dyes (including Ponceau 4R) and sodium benzoate have a small but measurable effect on the activity and attention of children.


  1. General Standard for Food Additives (Ponceau 4R)
  2. FDA Enforcement Reports (January 2012)
  3. European Food Safety Authority Reevaluation of Ponceau 4R
Posted in Colour, Food Additives, Ingredients

Carbon Black

Picture of a black splash

Carbon black

There are two black food dyes that seem to get confused. At least, they confuse me. The differences and the naming of the two are unclear. In fact, it seems that the same name, carbon black, is often used for both. They are:

  • Carbon Black (E 152), and
  • Vegetable Black (E 153)
Picture of a black splash for carbon black post

Carbon Black


Carbon Black

Carbon Black is an artificial food dye. Other names include Black 7984, Food Black 2, and C.I. 27755.

The chemical formula is C26H15N5Na4O13S4. In other words, it is made from carbon (C), hydrogen (H), nitrogen (N), sodium (Na), oxygen (O), and sulphur (S).

It is a brown-to-black azo dye.

It is not permitted in the U.S., E.U, Japan, or Australia1.


Vegetable carbon is produced by steam activation of carbonized vegetable material2. It can used both as a food colouring and as a medication (it can be used to absorb chemicals).

Other names include vegetable carbon, CI 77266, charcoal, Norit

The chemical formula is C3. That means, it is simply made from carbon (C), although there may also be impurities.

While approved for use in the European Union and Canada4, it has not been approved in the U.S.5


  1. Ingredients Wizard (Black 7984)
  2. European Food Safety Authority – Scientific Opinion on the re-evaluation of vegetable carbon (E 153) as a food additive
  3. Food and Agriculture Organization of the United Nations – Vegetable Carbon
  4. Qualitative determination of carbon black in food products
  5. Food Additives Permitted for Use In Canada
Posted in Colour, Food Additives, Ingredients

Brilliant Blue FCF

Brilliant Blue FCF


Brilliant Blue FCF is a food additive with an E number of 133. Additives with E numbers between 100 and 199 are generally used as food dyes.


Brilliant blue FCF is sometimes referred to as FD&C Blue No.1. It is an artifical dye produced from petroleum.  It is usually found as a red-blue powder. The chemical formula is C37H34N2Na2O9S3.

It is a triphenylmethane colour. Triphenylmethane dyes are composed of three hydrocarbon rings linked to a central carbon atom1.

Common Uses:

Brilliant Blue FCF is commonly used in popsicles, soft drinks, jell-o, icings, and sometimes even canned peas. Besides food, it is also commonly found in mouthwash and shampoo.

Besides being used as a blue dye, it can used in combinations with other food colours. For example, it is often used with Tartrazine to produce a green colour.

Some specific examples of foods containing brilliant blue include:

Health Issues / Side Effects:

However, when Brilliant Blue is used in hard candies and lollipops there is a risk that the dye can be absorbed through the tongue directly into the bloodstream. Once in the blood, it may inhibit mitochondrial respiration.3 My understanding is that this basically means that a cell’s ability to convert food to energy may be affected.


In the U.S., brilliant blue can only be used in food once the FDA certifies the batch2. Once certified, the FD&C Blue No.1 name can be used.


  1. The Chemistry of Colors
  2. Summary of Colour Additives for Use in the United States
  3. International Programme on Chemical Safety – World Health Organization

Further Reading

  1. Canadian Food Additive Dictionary
Posted in Colour, Food Additives, Ingredients

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