Litholrubine BK
5281-04-9 · Carmine 6B · CI Pigment Red 57 · E 180 · Rubinpigment · E180 · Calcium;(4Z)-4-[(4-methyl-2-sulfonatophenyl)hydrazinylidene]-3-oxonaphthalene-2-carboxylate · Litholrubine BK · Czerwień litolowa BK · LITHOL RUBINE BK · Lithol-rubine BK · Litholrubin BK · Litholrubine BK · Litol-rubina BK · Litolirubiini BK · Litolrubin BK · Litolrubina BK · Litolrubinas BK · Litolrubino BK · Litolrubīns BK · Litoolrubiin BK · Rubinpigment BK (litholrubin BK) · ΛΙΘΟΡΟΥΜΠΙΝΗ ΒΚ · Λιθορουμπίνη BK · ЛИТОЛРУБИН BK · Литолрубин ВКE number E180CAS 5281-04-9
Listed as a colour by the EU.
Listed as colours (EU)
- European Union: Colours — Regulation (EC) No 1333/2008, Annex II, Part B, 1. Colours (consolidated text 02008R1333-20260818)
Litholrubine BK is a synthetic red pigment with a single permitted use in the EU: colouring edible cheese rind.
Where it is and isn’t permitted
| Jurisdiction | Status | Scope and limits | Citation |
|---|---|---|---|
| Australia and New Zealand | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Canada | No listing matchedHealth Canada’s lists name additives without E or INS numbers, so this site matches them by exact name. A substance listed there under a name this site does not recognise has no row here. | ||
| European Union | Permitted, with conditions | 1 food category quantum satis. Period of application: from 1 August 2014. Note 67: Maximum limit for aluminium coming from aluminium lakes of E 120 cochineal, carminic acid, carmines and E 180 lit …quantum satis. Period of application: from 1 August 2014. Note 67: Maximum limit for aluminium coming from aluminium lakes of E 120 cochineal, carminic acid, carmines and E 180 litholrubine BK 10 mg/kg. No other aluminium lakes may be used. For the purposes of Article 22 (1) (g) of Regulation (EC) No 1333/2008 that limit shall apply from 1 February 2013. | Regulation (EC) No 1333/2008, Annex II, as amended by (EU) No 1129/2011retrieved 2026-10-18 |
| Great Britain | Permitted, with conditions | 1 food category quantum satis. Period of application: from 1 August 2014. Note (67): Maximum limit for aluminium coming from aluminium lakes of E 120 carminic acid, carmine and E 180 litholrubine …quantum satis. Period of application: from 1 August 2014. Note (67): Maximum limit for aluminium coming from aluminium lakes of E 120 carminic acid, carmine and E 180 litholrubine BK 10 mg/kg. No other aluminium lakes may be used. For the purposes of Article 22(1)(g) of this Regulation, that limit shall apply from 1 February 2013. | Assimilated Regulation (EC) No 1333/2008, Annex II (as at 28 June 2024)retrieved 2026-10-18 |
| Japan | No listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance. | ||
| South Korea | No listing matchedThis site imports Part III of South Korea’s Standards and Specifications for Food Additives, matched by CAS number, then INS number, then exact name. Mixed preparations and sanitisers are not imported, and an entry whose identifiers disagreed with a page’s is held for review, so an empty row does not show that South Korea does not permit the substance. | ||
| United States | Not listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited. | ||
| Codex Alimentarius | Not listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited. |
How much is permitted
A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.
| European Union | — | 1 quantum satis |
|---|---|---|
| Great Britain | — | 1 quantum satis |
No regulator sets a figure for Litholrubine BK. That is not an absence of control: where the listing says quantum satis or good manufacturing practice, the quantity is limited to what the effect requires.
What it is made from
A synthetic azo pigment produced from petroleum-derived aromatic intermediates and precipitated as its calcium salt, which is insoluble and stays on the rind.
- Vegan
- Vegetarian
Compare other additives on the dietary indexes.
- CAS registry number
- 5281-04-9
The two specifications, compared
The European Union sets identity and purity by regulation; JECFA publishes its own through FAO, advisory until a country adopts it. Both documents are below in full. These are the parameters each puts a number on.
| Parameter | European Union | JECFA |
|---|---|---|
| Assay | no less than 90 % | no less than 90 % |
| Lead | no more than 2 mg/kg | no more than 2 mg/kg |
| Arsenic | no more than 3 mg/kg | — |
| Mercury | no more than 1 mg/kg | — |
| Cadmium | no more than 1 mg/kg | — |
The two documents state the same figures for every parameter compared here.
How the EU defines it
The legal specification an additive must meet to be sold as this E number in the EU — what it is, how it may be made, and the purity it must reach. From Commission Regulation (EU) No 231/2012.
E 180 Litholrubine bk
Lithol Rubine BK consists essentially of calcium 3-hydroxy-4-(4-methyl-2-sulfonatophenylazo)-2-naphthalenecarboxylate and subsidiary colouring matters together with water, calcium chloride and/or calcium sulphate as the principal uncoloured components.
Synonyms: CI Pigment Red 57; Rubinpigment; Carmine 6B
Assay, identification and purity criteria
Description and assay
- Colour Index No
- 15850:1
- Einecs
- 226-109-5
- Chemical name
- Calcium 3-hydroxy-4-(4-methyl-2-sulfonatophenylazo)-2-naphthalene-carboxylate
- Chemical formula
- C₁₈H₁₂CaN₂O₆S
- Molecular weight
- 424,45
- Assay
- Content not less than 90 % total colouring matters [image] 200 at ca. 442 nm in dimethylformamide
- Description
- Red powder
Identification
- Spectrometry
- Maximum in dimethylformamide at ca. 442 nm
Purity criteria
- Subsidiary colouring matters
- Not more than 0,5 %
- 2-Amino-5-methylbenzenesulfonic acid, calcium salt
- Not more than 0,2 %
- 3-hydroxy-2-naphthalenecarboxylic acid, calcium salt
- Not more than 0,4 %
- Unsulfonated primary aromatic amines
- Not more than 0,01 % (expressed as aniline)
- Ether extractable matter
- From a solution of pH 7, not more than 0,2 %
- Arsenic
- Not more than 3 mg/kg
- Lead
- Not more than 2 mg/kg
- Mercury
- Not more than 1 mg/kg
- Cadmium
- Not more than 1 mg/kg
How JECFA defines it
The international specification for identity and purity, prepared by the Joint FAO/WHO Expert Committee on Food Additives and published by FAO. It is a different document from any above, written by a different body and revised on its own cycle; it is advisory, and a country adopts it or does not.
INS 180 Lithol Rubine BK
Consists essentially of calcium 3-hydroxy-4-(4-methyl-2-sulfonatophenylazo)-2-naphthalenecarboxylate and subsidiary colouring matters together with water, calcium chloride and/or calcium sulfate as the principal uncoloured components.
Synonyms: CI Pigment Red 57, FD & C Red No. 7, Brilliant Carmine 6B, Rubinpigment, Carmine 6B, Litholrubintoner BKL, Permanent Rubin L6B, CI (1975) No. 15850, INS No. 180 Brilliant Carmine 6B; Carmine 6B; CI (1975) No. 15850; CI Pigment Red 57; FD&C Red No. 7; Litholrubintoner BKL; Permanent Rubin L6B; Rubinpigment
Assay, identification and purity criteria
Description and assay
- Specification history
- Prepared at the 30th JECFA (1986), published in FNP 37 (1986) and in FNP 52 (1992). Metals and arsenic specifications revised at the 59th JECFA (2002). No ADI was allocated at the 30th JECFA (1987)
- Chemical names
- Calcium 3-hydroxy-4-(4-methyl-2-sulfonatophenylazo)-2-naphthalene-carboxylate
- C.A.S. number
- 5284-04-9
- Chemical formula
- C 18 H 12 CaN 2 O 6 S
- Formula weight
- 424.45
- Assay
- Not less than 90% total colouring matter
- DESCRIPTION
- Red powder
- FUNCTIONAL USES
- Colour
- METHOD OF ASSAY
- Place about 0.2 g of the sample, accurately weighed, in a 500-ml Erlenmeyer flask and add 5 ml of sulfuric acid. Mix well and add 100 ml of ethanol. Shake well, heat on a water bath. Add a solution made by dissolving 20 g of sodium hydrogen tartrate in 100 ml of boiling water and mix with 20 ml of 30% sodium hydroxide solution, shaking vigorously. Titrate with 0.1 N titanous chloride. Each ml of 0.1 N titanous chloride is equivalent to 10.61 mg of C 18 H 12 CaN 2 O 6 S.
Identification
- Solubility (Vol. 4)
- Slightly soluble in hot water (90 o ); insoluble in cold water; insoluble in ethanol
- Spectrophotometry (Vol. 4)
- Absorbance maximum at about 442 nm (in dimethylformamide)
Purity criteria
- Loss on drying at 135 o
- Not more than 10% together with chloride and sulfate calculated as
- (Vol. 4)
- calcium salts
- Lead (Vol. 4)
- Not more than 2 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.”
- Subsidiary colouring matters
- Not more than 0.5% See description under TESTS
- Organic compounds other than colouring matters
- Not more than 0.2% of 2-Amino-5-methylbenzenesulfonic acid, calcium salt Not more than 0.4% of 3-hydroxy-2-naphthalenecarboxylic acid, calcium salt See description under TESTS
- Unsulfonated primary aromatic amines
- Not more than 0.01% calculated as aniline See description under TESTS
- Ether extractable matter (Vol. 4)
- Not more than 0.2% Dry 2 g of the sample in a desiccator (sulfuric acid) for 24 h and extract using Method II
- Test: Chlorides (Vol. 4)
- Mix 1 g of the sample with 100 ml of water and let stand for 30 min, shaking occasionally. Filter and wash the residue with a small amount of water. Combine the washings with the filtrate. Acidify with 5 ml of 1.5 N nitric acid and titrate with 0.1 N silver nitrate solution as directed under Determination of Chloride as Sodium Chloride . Each ml of 0.1 N silver nitrate solution is equivalent to 0.00555 g of calcium chloride.
- Test: Sulfates
- Weigh accurately about 1 g of the sample, mix 100 ml of water and heat on a water bath for 10 min. Cool, filter and wash the residue with a small amount of water. Combine the washings with the filtrate. Dilute to 150 ml with water and acidify with hydrochloric acid, adding 1 ml in excess. Heat the solution to boiling and add an excess of 0.25 N barium chloride drop by drop, with stirring. Allow the mixture to stand on a hot plate for 4 h, or leave it overnight at room temperature and then bring it to about 80 o and allow the precipitate to settle. Filter off the precipitated barium sulfate, wash with hot water and ignite at a dull red heat in a tared crucible until a constant weight is obtained. Carry out a blank determination and apply any necessary correction. Calculate the % of sulfate as calcium sulfate from:
- Test: Subsidiary colouring matters
- Boil 0.10 g of sample gently with 100 ml of glacial acetic acid and with 75 ml of 8 N hydrochloric acid until the colour has dissolved. Cool and transfer the solution to a 1000 ml separatory funnel, washing any residual solution into the funnel with small portions of acetic acid. Extract the acidic solution with 150 ml of ether and separate the miscible solution formed by adding about 150 ml of water. Transfer the lower layer to a second funnel and extract with another 100 ml of ether. Combine the ether extracts and wash with 100 ml portions of water until the washings are colourless, and twice more after the last colourless washings. Remove the subsidiary colour from the ether layer by extraction with 20 ml portions of 2% sodium hydroxide. Warm to expel the ether. Determine the colour concentration spectrophotometrically at 505 nm. Standard: 3-Hydroxy-4-(4-methylphenylazo)-2-naphthalenecarboxylic acid has an absorptivity of 0.032 L mg -1 cm -1 at 505 nm.
- Test: Organic compounds other than colouring matters (Vol. 4)
- Use 10% ammonium sulfate in place of the 25% ammonium sulfate listed in the method. Add 100 ml eluant to 5 g cellulose, stir, allow to settle and decant. Place 0.100 g of the colour sample in a beaker and add 5 ml ethanol. Stir to ensure complete wetting of the sample. Transfer the 5 g cellulose to the beaker containing the sample. Add 10 g ammonium sulfate and stir thoroughly. Transfer the mixture to the column. Rinse the beaker with 25 ml eluant, adding the rinse to the column. Then follow the procedure detailed in the Determination by Column Chromatography.
- Test: Unsulfonated primary aromatic amines (Vol. 4)
- Mix 2 of the sample well with 150 ml of toluene and boil gently for 5 min. Filter after cooling and wash the residue with a small amount of toluene. Combine the washing with the filtrate and extract with three 10-ml portions of N hydrochloric acid and dilute the combined extracts to 100 ml with water. Follow the procedure detailed in the method Unsulfonated primary aromatic amines .
Every name it appears under
26 recorded names. A label may use any of them.
E number
- E180
CAS registry number
- 5281-04-9
As it appears in regulation
- Litholrubine BK
Other names
- Carmine 6B
- CI Pigment Red 57
- E 180
- Rubinpigment
Systematic names
- Calcium;(4Z)-4-[(4-methyl-2-sulfonatophenyl)hydrazinylidene]-3-oxonaphthalene-2-carboxylate
The EU re-evaluation programme
Every additive authorised in the EU before 20 January 2009 was put back through EFSA by Commission Regulation (EU) No 257/2010, and this one is named in it. What the Regulation required is below; whether the opinion has since been published is not something this site records.
- To be evaluated by 15 April 2010. Named in Annex II, Part I, point 1 as “Litholrubine BK”, among the additives given priority within its class.
Hazard reference values
| Type | Value | Population | Assessed by | Opinion |
|---|---|---|---|---|
| ADI | not allocated | — | JECFA | 1986 |
Evidence and how bodies read it
What assessing bodies concluded
Each conclusion is paraphrased in the body's own framing, from the published opinion linked beneath it. Where bodies differ, both stand; this site does not adjudicate between them or add a view of its own.
EFSA 2010
The ANS Panel considered the database for Litholrubine BK (E 180) too limited to support the SCF's ADI of 1.5 mg/kg bw/day or to set a new one, and concluded that the ADI should be withdrawn. Because the highest anticipated exposure was around 1,700-fold below the effect level identified in rats, it considered a significant safety concern unlikely for the single authorised use in edible cheese rinds.
Common questions
Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.
- What is E 180?
- E 180 is Litholrubine BK. Litholrubine BK is a synthetic red pigment with a single permitted use in the EU: colouring edible cheese rind.
- What is Litholrubine BK used for in food?
- It is listed as a colour — the role the EU assigns it. This page shows every function each regulator records, with the citation for each.
- Where is Litholrubine BK permitted?
- Of the seven regulators this site reads, the EU and Great Britain permit it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
- Is Litholrubine BK vegan?
- Yes. Litholrubine BK is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.
Sources for this page
- eu retrieved 2026-10-18
- gb retrieved 2026-10-18
- euspecs retrieved 2026-10-18
- jecfaspecs retrieved 2026-09-23
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