Content uploaded by Yasha Nazir Butt
Author content
All content in this area was uploaded by Yasha Nazir Butt on May 19, 2016
Content may be subject to copyright.
Pak. J. Biochem. Mol. Biol. 2016; 49(1): 29-35
Review
SUDAN DYES AND THEIR POTENTIAL HEALTH EFFECTS
*1Alim-un-Nisa, 2Naseem Zahra, 3Yasha Nazir Butt
1, 2 Food and Biotechnology Research Centre (FBRC)
PCSIR Laboratories Complex, Ferozepur Road Lahore-54600, Pakistan
3Institute of Biochemistry and Biotechnology, University of the Punjab, Lahore.
Abstract: Sudan dyes are synthetic, oil-soluble, red coloured azo dyes which are not permitted by the
authorities in Switzerland, Japan, Europe, and the United States for the purpose of food colouring. Sudan
dyes I, II, III, IV, and their degradation products are considered harmful to human health due to their
teratogenicity, genotoxicity, and carcinogenicity which leads to cancer. Many experimental studies on animal
specimen have confirmed the formation of tumour due to the presence of different Sudan dyes in food
products. Sudan dyes are described to have sensitising characteristics; they easily get absorbed through
dermal route and airways and causes health problems. This paper discusses the harmful effects of Sudan dyes
on human health which is now greatly used in foodstuffs.
Keywords: Sudan dyes, Illegal, Health effects
Received: January 11, 2016 Accepted: February 15, 2016
*Author for Correspondence: nisaalim64@yahoo.com
Introduction
For food industries, colour is the most distinguished
and significant characteristic of food products.
Many colorants are often added to different foods
for the enhancement of visual aesthetics and
promotion of sales. Colour additives are widely
used for the reinforcement and uniformity of foods
which already have some colours present in them.
Sudan dyes are industrial synthetic azo dyes which
are traditionally used in waxes, drugs, plastics, oils,
food, clothing, polishes, and are also used in
histochemical analysis 1. The International Agency
for Research on Cancer has classified these dyes as
Class-III carcinogens and it has now banned Sudan
dyes worldwide; however, many countries still
utilize azo-dyes like Sudan dyes illegally in their
food products 2. Although animal studies have
proven Sudan dyes as carcinogenic substances,
these colorants have recently been found in various
food products in some European countries. These
colouring agents are added to different foods
including chili powder to intensify, mimic, and
prolong good appearance which are similar to the
natural red colours. In the United Kingdom, more
than six hundred food products containing Sudan
dyes have been found such as Worcestershire sauce,
pizza, noodle soup, and fish sauce. These food
additives are considered illegal to use in food stuffs
according to the FAD and EU. The European
commission now demands the product
documentation in order to confirm the absence of
harmful Sudan dyes. A detection limit of 0.5 to 1
mg/kg has been set by the EU for Sudan dyes. Any
food material which contains dyes above the
permissible limits is completely withdrawn from
market. The European Food Safety Authority
(EFSA) initiated a review in 2005, regarding the
toxicology of various dyes found illegally in food
products. EFSA concluded their research with the
strong evidence of genotoxicity and carcinogenicity
caused by several dyes especially Sudan I. Since
Sudan-I structurally resembles all other Sudan dyes,
the larger group is found to have the same harmful
effects 3. Illegal dyes create major economic
consequences for public health and food industries;
therefore, there must be some rapid, inexpensive,
simple, and reliable analytical method to minimize
adverse effects of azo-dyes. Many researchers are
working on these analytical methods, but still there
is dire need of more quantitative methods for better
analysis 4-6. Sudan dyes are widely used in textile
industry and as a result waste water produced from
textile industries damages aquatic life. It may also
prove to be of deleterious effect for humans who
consume seafood which lives in dye contaminated
water 7, 8.
Sudan Dyes - Basic Facts
Sudan dyes are of red-orange colours which are very
often used for colouring purposes in food to enhance
the quality and hence to promote sales 9. Foods are
usually assessed on the basis of their colour and texture
10. The effect of azo-dyes not only brings about harmful
effects to human health but it also leaves adverse
environmental effects. Due to the formation of dyestuff
for textile industry, wastewater has largely
contaminated sea water hence causing damage to
marine life 11, 12. Naphthylamine is another
degradation product of Sudan dyes which aggravates
metabolism and causes potential risk to health 13.
Figure 1: Sudan Dyes
30 Sudan dyes potential health effects
It was mid-19th century when all colouring agents
and dyes were obtained from natural sources including
plants and animals. Later, in the beginning of 20th
century it got replaced by synthetic colours
manufactured in industries. Today we find many
pigments and dyes which are synthetic in nature and are
produced commercially. Each year new coloured
compound agents hits the market and is utilized to
enhance the appearance of various food and household
items 14.
Various sorts of Sudan Dyes
A variety of Sudan dyes include Sudan I, Sudan II,
Sudan III, Sudan IV, Sudan Black B, Sudan Orange G,
Sudan Red B, Sudan Red G, and Sudan Red 7B 15.
Sudan I and IV dyes are reported to be present in
sauces, curry, chili powders, spice mixtures, and
seasonings. Sudan dye I is often formed as an impurity
when preparing sunset yellow colour. It also widely
attributes to the release of metabolic substances
including 1-amino-2-napthol and aniline which
aggravate the incidence of carcinoma 16. An experiment
on mice specimen fed on food comprising Sudan I
concluded the occurrence of spleen tumour 17.
Although European Union strictly banned the usage
of Sudan Dyes, but around 20 cases per year were
reported due to the consumption of imported food
products containing Sudan dyes 18. Studies have shown
that Sudan dye II cause SIV local and bladder
carcinoma in mice 19. Sudan dye II, III, and IV
resemble Sudan dye I structurally and hence they all
contribute to genotoxicity 20. In an experimental study,
Sudan Red 7b and Deep black BB were used to stain
the termites and as a result a very low mortality rate of
termites was seen which were stained with Sudan Red
7B 21.
Sudan Dyes - Food Issues
Many food products were detected by EU including
chili samples which were found contaminated with
synthetic dyes. Other contaminated foodstuffs included
chutneys, number of relishes, and seasonings. Since
synthetic dyes count as risk to human health, they are
prohibited in many countries 22. These dyes produce
biologically active compounds which cause intense
harm to body since they act as harmful toxins 23. In
United Kingdom warnings have been provided by Food
Standards Agency (FSA) regarding the presence of
Sudan dye I in frozen meat products, spices, and chips
24. Sudan dyes are mostly absent in fresh food products
like fresh chilies; however, the addition of Sudan dyes
bring about genotoxic effects and carcinogenicity of
bladder and liver of mammals 25.
Table 1. Statuary Basis for Permissible LimitsThe Federal Office of
Public Health has set the standard permissible limits for the Sudan dyes.
Federal Office of Public health, 2004 37
Sudan Dyes - Health Effects
Not only Sudan dyes but also their degradation products
are quite carcinogenic, teratogenic, and harmful to
human health. Studies have proven that the exposure of
synthetic dyes along with sodium benzoate
preservatives cause hyperactivity in 3 years old and 8-9
years old children. Sudan dyes present in food products
leave adverse effect on the attention, behaviour, and
activity of children 26. Sudan dyes reduce to form their
corresponding amines when in taken orally. This
reduction is caused mainly by the extra hepatic tissues,
gastrointestinal microbes, and liver cystolic reductase
27.
Many laboratory experiments on animals have
shown mutagenic and carcinogenic effects due to the
release of amines. These carcinogenic amines make
Sudan dyes as potential health hazards 28. The
experimental studies were done on rats fed on feed
containing Sudan dye I which gave way to high level of
neoplastic liver nodules formation causing lymphoma
and leukaemia. Moreover, the implantation of Sudan I
dye inside the urinary bladder of animal specimen
caused bladder carcinoma. Henceforth, Sudan dyes are
mutagenic and carcinogenic both Invivo and invitro 29.
Sudan dyes have also been found to cause genotoxic
effect in colon and stomach of mice 30.
Sudan dyes may take access to body through skin
when hair dyes containing Sudan dyes are applied. This
may be quite harmful since it results in carcinogenic
amines 31, 32. Sudan dyes activate P1-450 associated
enzymes which are found in animals hence aggravating
immunotoxic effects. Sudan dyes are indirect
carcinogens (classified as category 3 carcinogens by
IARC) and are therefore proscribed from the use in
foods 33, 34. The invitro experimental analysis has
demonstrated that Sudan dyes present in human
microsomes creates DNA adduct. The peroxisomes also
get activated by Sudan dyes to produce Protein, DNA,
and RNA adducts 35, 36.
The illegal presence of Sudan dye I in food products in
EU was first reported in May, 2003. A decision against
the usage of Sudan dyes was given by EU as a reaction
to the occurrence of Sudan dyes in red chili which was
first imported from India in France 38. It was observed
that chili powder and all those food products containing
chili powder contained Sudan dyes. Since then, many
EU Member States through Rapid Alert System for
Food and Feed (RASFF) notified regarding the
presence of Sudan dye I and IV in sumac, curcuma, and
palm oil. Many notifications of Sudan II and III dyes
were also received for the similar range of food
products. It was discovered that the food products
Factor
Evaluation
Sudan 2
0.1 mg/kg (limit
value)
Sudan 3
0.1 mg/kg (limit
value)
Sudan 4
0.1 mg/kg (limit
value)
Nisa et al. 31
containing Sudan dyes were manufactured from the
contaminated raw products obtained from countries
outside the EU including India, Ghana, Egypt for raw
spices, Nigeria, Pakistan, and West Africa for palm oil.
The primary origin of Sudan dyes include the raw
materials which are used as important ingredients by
the EU for the production of processed food products
39.
Measures for prevention
There are a number of steps which can be
taken in order to prevent Sudan from entering the food
chain resulting in spice adulteration. If there is any
product which comprises of Sudan dyes beyond
permissible limits, should be destroyed. Contaminated
raw materials should be avoided because failure to
remove dyes from supply chain would result in
amelioration of contamination. Many health sectors and
companies are working with local authorities and food
industries to avoiding foods containing Sudan dyes by
removing products from sale in the retail outlets.
Companies should familiarize themselves with the
vendors and control the amount of Sudan dyes in raw
materials. For that, the certificate warrants must be
ensured and strict action must be taken if adulteration
of Sudan dyes is done with spices. In order to maintain
the integrity of supply-chain, we need to have
surveillance programs as well as system for solid
inspection. Laws must be enforced to minimize the
utilization of many foods which contain these
carcinogenic dyes 40.
The production and application of Sudan dyes adds
insoluble dye agents in the effluents when industries
remove them as unwanted matter. However, scientists
have initiated experiments to identify and isolate some
bacterial species which help in reducing these azo-dyes.
Many other microbial strains must be used to
decontaminate raw materials before they are used to
produce fine products. 41.
Conclusion
Synthetic dyes are known to be highly stable to oxygen,
light, and pH; they are scarcely contaminated by
microbes, have low production cost, and provide good
colour uniformity. Despite of all good characteristics
these dyes must not be used due to their carcinogenicity
and teratogenicity. As an alternative, natural dyes
which are quite expensive and unstable may be
processed further and utilized to prevent any potential
health hazard.
There is a great impact of illegal dyes on public
health therefore accurate, sensitive, and selective
methods should be introduced so that to detect and
quantify the synthetic food dyes in different foods. All
the raw materials and finished products must be
labelled clearly if they contain azo-dyes in them. Those
items which contain Sudan dyes must be discarded as
hazardous waste products. The amount of consumption
of synthetic dyes plays a great role in risks for cancer.
Occasional and very low consumption of Sudan dyes
through foods which are rarely consumed might not be
as much risky as continuous and high doses but risk still
exist. Experts give their opinion to keep the exposure of
Sudan dyes quite low to attain the safety level and
avoid health relating risks.
References:
1. IARC Monograph. Evaluation of Carcinogenic
Risk of Chemicals to Man, Vol. 8. World
Health Organization, Geneva, Switzerland;
1975.
2. Monographs on the Evaluation of Carcinogenic
Risks to Humans. Some aromatic azo
compounds, summary of data reported and
evaluation, world health organization,
international agency for research on cancer
(IARC) IARC, 2008; Volume 8. Website:
(http://monographs.iarc.fr/ENG/Monographs/vo
l8/volume8.pdf) accessed 27th June, 2008.
3. “Opinion of the Scientific Panel on Food
Additives, Flavourings, Processing Aids and
Materials in Contact with Food on a request
from the Commission to review the toxicology
of a number of dyes illegally present in food in
the EU” The EFSA Journal, 2005; 263, 1–71.
4. Mazzetti, M., Fascioli, R., Mazzoncini, I.,
Spinelli, G., Morelli, I., & Bertoli, A.
Determination of 1-phenylazo-2-naphthol
(Sudan I) in chilli powder and in chilli-
containing food products by GPC clean-up and
HPLC with LC/MS confirmation. Food
additives and contaminants, 2004; 21(10), 935-
941.
5. Pielesz, A., Baranowska, I., Rybak, A., &
Włochowicz, A. Detection and determination of
aromatic amines as products of reductive
splitting from selected azo dyes. Ecotoxicology
and environmental safety, 2002; 53(1), 42-47.
6. Cornet, V., Govaert, Y., Moens, G., Van Loco,
J., & Degroodt, J. M. Development of a fast
analytical method for the determination of
Sudan dyes in chili-and curry-containing
foodstuffs by high-performance liquid
chromatography-photodiode array detection.
Journal of agricultural and food chemistry,
2006; 54(3), 639-644.
7. Chang, J. S., Chou, C., Lin, Y. C., Lin, P. J., Ho,
J. Y., & Lee Hu, T. Kinetic characteristics of
bacterial azo-dye decolorization by< i>
Pseudomonas luteola</i>. Water Research,
2001; 35(12), 2841-2850.
8. Zhao, X., & Hardin, I. R. HPLC and
spectrophotometric analysis of biodegradation
of azo dyes by< i> Pleurotus ostreatus</i>.
Dyes and pigments, 2007; 73(3), 322-325.
9. Downham, A., & Collins, P. Colouring our
foods in the last and next millennium.
International journal of food science &
technology, 2000; 35(1), 5-22.
10. Perva-Uzunalić, A., Škerget, M., Weinreich, B.,
& Knez, Ž. Extraction of chilli pepper (var.
Byedige) with supercritical CO< sub> 2</sub>:
Effect of pressure and temperature on
capsaicinoid and colour extraction efficiency.
Food chemistry, 2004; 87(1), 51-58.
32 Sudan dyes potential health effects
11. Pandey, A., Singh, P., & Iyengar, L. Bacterial
decolorization and degradation of azo dyes.
International Biodeterioration &
Biodegradation, 2007; 59(2), 73-84.
12. Saratale, R. G., Saratale, G. D., Chang, J. S., &
Govindwar, S. P. Bacterial decolorization and
degradation of azo dyes: a review. Journal of the
Taiwan Institute of Chemical Engineers, 2011;
42(1), 138-157.
13. Ali MO, Al-Ghor A, Sharaf AK,
Mekkawy H, Montaser MM. Genotoxic
effects of the food color (carmoisine) on the
chromosome of bone marrow cells of rat.
Toxicol Lett. 1998; 95(Suppl. 1):44.
14. A. Majcen-Le Marechal, Y. M. Slokar
and T. Taufer. “Decoloration of Chlorotriazine
Reactive Azo Dyes with H2O2/UV,” Dyes
Pigments, 1997; 33, pp. 281-298.
15. ESA. ESA advice to members non-permitted
colours in spices; 2008. Available from:
http://www.esa-spices.org/content/
pdfs/ESAAdvicerev4final.pdf
16. NTP. National Toxicology Program Technical
Report No. 226. 1978. Carcinogenesis Bioassay
of C.I. Solvent Yellow 14 in F344/N Rats and
B6C3F1 Mice (Feed Study).
17. CIIT. Chemical Industry Institute of
Technology. Final Report, 104-Week Chronic
Toxicity Study in Rats, Anilin Hydrochloride,
Research Triangle Park, NC, USA; 1982.
(Quoted from Draft RAR Anilin, 13.02.2002
und CSTEE, 2003).
18. Anderton, S. M., Incarvito, C. D., & Sherma, J.
Determination of Natural and Synthetic Colors
in Alcoholic and Non Alcoholic Beverages by
Quantitative HPTLC. Journal of liquid
chromatography & related technologies, 1997;
20(1), 101-110
19. International Agency for Research on Cancer.
IARC Monographs on the evaluation of
carcinogenic risks to humans. Some
aromatic azo compunds. IARC, Lyon,
1975; vol. 8. Available at
http://monographs.iarc.fr/ENG/Monographs/vol
8/ volume8.pdf. Accessed 1 Sep 2009
20. European Food Safety Authority (EFSA).
Opinion of the Scientific Panel on Food
Additives, Flavourings, Processing Aids and
Materials in Contact with Food on a
request from the Commission to Review
the toxicology of a number of dyes illegally
present in food in the EU. The EFSA J, 2005;
263:1–71
21. Lai, P. Y., Tamashiro, M., Fujii, J. K., Yates, J.
R., & Su, N. Y. Sudan Red 7B, a dye marker for
Coptotermes formosanus, 1983.
22. Mejia, E., Ding, Y., Mora, M. F., & Garcia, C.
D. Determination of banned sudan dyes in chili
powder by capillary electrophoresis. Food
Chemistry, 2007; 102(4), 1027-1033.
23. Minioti, K. S., Sakellariou, C. F., & Thomaidis,
N. S. Determination of 13 synthetic food
colorants in water-soluble foods by reversed-
phase high-performance liquid chromatography
coupled with diode-array detector. Analytica
Chimica Acta, 2007; 583(1), 103-110.
24. FSA (2006). <http://www.food.gov.uk>,
accessed October 15, 2006.
25. Xu, H., Heinze, T. M., Paine, D. D., Cerniglia,
C. E., & Chen, H. Sudan azo dyes and Para Red
degradation by prevalent bacteria of the human
gastrointestinal tract. Anaerobe, 2010; 16(2),
114-119.
26. McCann, D., Barrett, A., Cooper, A., Crumpler,
D., Dalen, L., Grimshaw, K. & Stevenson, J.
Food additives and hyperactive behaviour in 3-
year-old and 8/9-year-old children in the
community: a randomised, double-blinded,
placebo-controlled trial. The Lancet, 2007; 370
(9598), 1560-1567.
27. SCCNFP, The Scientific Committee on
Cosmetic Products and Non-Food Products
Intended for Consumers: Opinion concerning p-
Phenylenediamine (Colipa A 7) adopted by the
SCCNFP during the 19th plenary meeting, 27
February 2002. Available at
http://europa.eu.int/comm/food/fs/sc/sccp/outco
me_en.html.
28. DFG, Deutsche Forschungsgemeinschaft,
Senatskommission zur Prüfung
gesundheitsschädlicher Arbeitsstoffe. MAK-
und BAT-Werte-Liste 2003. Mitteilung 39.
WILEY-VCH-Verlag, Weinheim.
29. AGS. Ausschuss für Gefahrstoffe.
Begründungen zur Bewertung von Stoffen als
krebserzeugend, erbgutverändernd oder
fortpflanzungsgefährdend. Anilin (October
2002), 1-phenylazo-2-naphthol (Sudan I)
(November 1997)
http://www.baua.de/praz/ags/begr_905.htm
30. Tsuda, S., Matsusaka, N., Madarame, H., Ueno,
S., Susa, N., Ishida, K. & Sasaki, Y. F. The
comet assay in eight mouse organs: results with
24 azo compounds. Mutation Research/Genetic
Toxicology and Environmental Mutagenesis,
2000; 465(1), 11-26.
31. Platzek, T., Lang, C., Grohmann, G., Gi, U. S.,
& Baltes, W. Formation of a carcinogenic
aromatic amine from an azo dye by human skin
bacteria in vitro. Human & experimental
toxicology, 1999; 18(9), 552-559.
32. Zhang, Y. P., Zhang, Y. J., Gong, W. J.,
Gopalan, A. I. and Lee, K. P. Rapid separation
of Sudan dyes by reverse-phase high
performance liquid chromatography through
statistically designed experiments. J.
Chromatogr. A, 2005; 1098: 183-187.
33. Anonymous. Opinion of the scientific panel on
food Additives, Flavourings, Processing Aids
and Materials in contact with food (AFC) to
review the toxicology of a number of dyes
illegally present in food in the EU. EFSA
journal, 2005; 264: 1-71.
34. M Masarat Dar, Wani Idrees and FA Masoodi.
Detection of Sudan Dyes in Red Chilli Powder
by Thin Layer Chromatography, Open Access
Scientific Reports, 2013; 2(1):1-3.
Nisa et al. 33
35. Stiborová, M., Martínek, V., Rýdlová, H.,
Hodek, P., & Frei, E. Sudan I Is a Potential
Carcinogen for Humans Evidence for Its
Metabolic Activation and Detoxication by
Human Recombinant Cytochrome P450 1A1
and Liver Microsomes. Cancer Research, 2002;
62(20), 5678-5684.
36. Stiborova, M., Martinek, V., Schmeiser, H. H.,
& Frei, E. Modulation of CYP1A1-mediated
oxidation of carcinogenic azo dye Sudan I and
its binding to DNA by cytochrome b5. Neuro
endocrinology letters, 2006; 27, 35-39.
37. Federal Office of Public Health: Memo No. 97:
Banned Sudan dyes, Sudan I – IV in foodstuffs,
Berne, 22.6. 2004
38. Commission decision (E.C) n. 460/2003 of 20
June 2003. Off. J. Eur. Union, L., 154, 114,
2003.
39. RASFF. Rapid Alert System for Food and Feed
(RASFF) Annual Report of the Functioning of
the RASFF 2004. Version 2 of 06-04-2005.
Available on:
http://europa.eu.int.comm/food/food/rapidalert/r
eport2004_en.pdf accessed on 21 June 2005.
40. Calbiani, F., Careri, M., Elviri, L., Mangia, A.,
Pistara, L., & Zagnoni, I. Development and in-
house validation of a liquid chromatography–
electrospray–tandem mass spectrometry method
for the simultaneous determination of Sudan I,
Sudan II, Sudan III and Sudan IV in hot chilli
products. Journal of Chromatography A, 2004;
1042(1): 123-130.
41. Platzek, T., Lang, C., Grohmann, G., Gi, U. S.,
& Baltes, W. Formation of a carcinogenic
aromatic amine from an azo dye by human skin
bacteria in vitro. Human & experimental
toxicology, 1999; 18(9): 552-559.