Dioxins and Dioxin-like Compounds in Foods and Feeds

October 2020

Executive Summary

  • The term dioxins includes: polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and dioxin-like polychlorinated biphenyls (DL-PCB)
  • Dioxins are ubiquitous, persistent and highly toxic environmental contaminants, which can compromise the reproductive and developmental systems, and can also interfere with hormone activity
  • PCDD and PCDF are not commercially manufactured. They are by-products in the manufacture of organo-chlorine chemicals, and are also produced during the combustion of chlorine-containing waste
  • PCB (including DL-PCB) were widely used in the manufacture of electrical, heat transfer and hydraulic equipment, until their production was abandoned in most countries in the 1970s
  • The most significant exposure route for most people is via their diet
  • Dioxins are found at low levels in all foods, especially oily or fatty food of animal origin, from species close to the top of the food chain
  • Levels of dioxins are decreasing as pollution control measures, introduced some decades ago, have an impact on the environment

Keywords:  dioxins, PCB, risk assessment; dietary exposure; incidents; food contaminants, environmental contaminants

Introduction

Dioxins and dioxin-like compounds (DLC) are members of a group of chemical compounds that are described as persistent organic pollutants (POP). Some POP are highly toxic and carcinogenic, although their toxicity varies greatly.

The POP addressed in this information statement are:

  • Polychlorinated dibenzo-p-dioxins (PCDD)
  • Polychlorinated dibenzofurans (PCDF)
  • Dioxin-like polychlorinated biphenyls (DL-PCB)

PCDD, PCDF and DL-PCB are three of the so-called ‘dirty dozen’ compounds identified as candidates for control and elimination, after the institution of the Stockholm Convention on POP in 2001. They are collectively referred to as ‘dioxins’ within this information statement.

PCDD and PCDF are unintentional by-products of human activity, especially the combustion of chlorine-containing compounds.

PCB (including DL-PCB) are non-flammable and chemically stable with a high boiling point and electrical insulating properties. Consequently, although their production was abandoned in most countries in the 1970s, PCB were widely used in electrical, heat transfer and hydraulic equipment, and a variety of other applications.

Dioxins occur in the environment throughout the world and accumulate in the food chain, mainly in the fatty tissue of animals. Animal feeds and feed additives are major sources of contamination for food of animal origin, including eggs, meat, fish and milk. They are highly toxic and can compromise the reproductive, developmental and endocrine systems. Given their toxicity, levels of dioxins in feed and food are regulated in Europe, the USA and other countries. Consequently, reliable methods are required for the sampling and analysis of dioxins.

Polychlorinated dibenzo-p-dioxins (PCDD) & Dibenzofurans (PCDF)

PCDD and PCDF are a group of relatively stable lipophilic organic substances comprising two groups of tricyclic planar compounds (Figure 1). Depending on the number of chlorine atoms and their positions in the rings, 75 PCDD and 135 PCDF (termed ‘congeners’), can occur. Only 17 of these are relatively persistent in animals and humans and therefore considered relevant.

Figure 1. Structure of PCDD and PCDF: Clx + Cly = 1-8.

These compounds have never been produced on an industrial scale and have no technological use. PCDD and PCDF are unintentional by-products of human activity. For example, they are produced by waste incineration, by burning biomass fuels, during iron ore sintering, and by forest fires. The production of dioxins is facilitated by the presence of chlorine and/or copper (as a catalyst), in the combustible material. The formation of dioxins can be enhanced by the presence of contaminants in biomass, including pesticides, wood preservatives and paint, which can introduce additional chlorine, metal catalysts, and even dioxin-precursors into combustion systems.                 

PCCD and PCDF are also present in the effluent discharge of pulp and paper mills, as a result of chlorine bleaching; and are also produced in the manufacture of some organochlorine chemicals, when these processes are not effectively controlled.

Dioxin-like polychlorinated biphenyls (DL-PCB)

DL-PCB are a sub-group of the wider class of PCB which demonstrate a similar toxicity to PCDD and PCDF.

PCB are a group of organochlorine compounds that are non-flammable and chemically stable with a high boiling point and good electrical insulating properties. They are synthesised by the catalysed chlorination of biphenyl. Depending on the number of chlorine atoms (1-10), and their position in the two rings, 209 different congeners are possible. Figure 2 shows the structure of PCB and the numbering of the carbon atoms in the two rings.

Figure 2. Structure of PCB: Cly + Clx = 1-10.

In contrast to PCDD and PCDF, PCB had widespread use in numerous industrial applications, generally in the form of complex technical mixtures. They were produced with an estimated total world production of 1.2-1.5 million tonnes, between 1929 and the end of the 1970s, when their production was abandoned in most countries, due to concerns about their toxicity and persistence in the environment and biota. Because of their physicochemical properties, PCB were widely used in a number of industrial and commercial applications. Technical PCB mixtures were mobile oils, viscous liquids or sticky resins, depending on the degree of chlorination (21 - 68% chlorine). Various commercial mixtures were produced with different trade names, such as Aroclor, Kanechlor, Declor and Clophen. PCB were used as insulating fluid in electrical transformers, and as heat exchange fluids. As a result of their widespread use, leakages, improper disposal practices and persistence, PCB also have a global distribution in the environment. Depending on the number and position of the chlorine atoms in the molecule, some of them are poorly degraded and, due to their lipophilic properties, are bioaccumulated in the food chain.

The PCB Elimination Network (PEN) develops and implements an awareness raising strategy, including videos, website, webinars and fact sheets, to ensure that PCB remain on the international agenda. It also supports PCB activities within the Basel, Rotterdam and Stockholm Conventions Conferences, and the United Nations Environment Assembly.

Dioxins in feed and food supply chains

Dioxins deposited on land and in waterways, in the form of contaminated soil (e.g. pastureland) and/or contaminated animal feed, are ingested by a variety of animals used as human food. Given their lipophilic nature, dioxins accumulate in the fat tissues of animals and some organs. (Fries, 1995). Proteins in the liver, for example, can bind dioxins.

Animal feed from a variety of origins may be contaminated including plants, animals, minerals, fish, and feed additives. Food of animal origin which may be contaminated by dioxins includes meat, meat products (eggs, cows’ milk, sheep, pigs, poultry, fish and eels). Dioxins may also occur in cereals, oilseeds, fruit and vegetables (including fresh herbs).

The risk for animal and human health, related to the presence of dioxins and DL-PCB in feed and food, has been evaluated by the EFSA Panel on Contaminants in the Food Chain (CONTAM) (EFSA, 2018):

According to the terms of reference provided by the European Commission, the scientific opinion should, inter alia, comprise the:

• evaluation of the toxicity of dioxins and DL-PCB for animals and humans, considering all relevant adverse acute and chronic health effects

 • estimation of the dietary exposure (chronic and, if relevant, acute dietary exposure) of the EU population including the consumption patterns of specific (vulnerable) groups of the population (e.g. high consumers, children, people following a specific diet, etc.)

 • estimation of the exposure of the different animal species to dioxins and DL-PCBs from feed and the levels of transfer/carry-over from the feed to the products of animal origin for human consumption

• assessment of the chronic (and if relevant acute) human health risks for the EU population including for specific (vulnerable) groups of the population as the consequence of the estimated dietary exposure

• assessment of the animal health risks for the different animal species as the consequence of the estimated exposure from animal feed’.

Selected outputs from the EFSA Panel’s evaluation are reported in the sections, below:

Toxicity of dioxins

 

Dioxins in the food chain are of concern because of a number of adverse health effects that can occur at very low levels of exposure. Acute exposure at relatively high level can result in chloracne (a skin condition), but of perhaps greater concern are the chronic effects of low-level exposure (typically through the diet) which can cause reproductive, carcinogenic and other effects (Faqi et al., 1998) (COC, 2001).

 

Toxic Equivalency Factors (TEF) and Toxic Equivalents (TEQ)

The most toxic dioxins are 2,3,7,8-TCDD and 1,2,3,7,8-PeCDD which are given Toxic Equivalency Factors (TEF) of 1. All other dioxins are compared to these and given comparative TEF (see Table 1).

In order to compare the toxicity of a mixture of congeners, Toxic Equivalents (TEQ) based on the TEF of the individual congeners are calculated. This scheme assumes that the relevant PCDD/F and DL-PCB bind to the intracellular aryl hydrocarbon receptor (AHR), and cause the same type of AHR-mediated biochemical and adverse effects. Another important requirement of the TEQ concept is the persistence and accumulation of the compounds in the body. 

 

To calculate the total TEQ value of a sample, the concentration of each congener is multiplied by its TEF and the products are then added together. The resulting TEQ value expresses the toxicity of PCDD/F and DL-PCB in a complex sample relative to the two most toxic dioxins. The current TEF values were proposed by the World Health Organization (WHO) in 2005 and are termed WHO 2005- TEF (van den Berg et al., 2006) based on the year of the WHO expert meeting (Table 1). Older analytical data, especially if generated before 2005, is generally reported as WHO1998-TEQ, I-TEQ or Nordic-TEQ. When interpreting TEQ results and evaluating, for example trends in the levels or exposure, it is important to know which TEF were used.

 

The TEQ value is calculated as follows:   TEQ = S [PCDDi ´ TEFi] +S [PCDFi ´ TEFi] + S [PCBi ´ TEFi]

 

Table 1. Toxic equivalency factors (TEF) established by WHO in 2005 (van den Berg et al., 2006).

Congener

WHO2005-TEF

 

Congener

WHO2005-TEF

 

PCDDs

 

 

Non-ortho PCBs

 

 

2,3,7,8-TCDD

1

 

PCB-77

0.0001

1,2,3,7,8-PeCDD

1

 

PCB-81

0.0003

 

1,2,3,4,7,8-HxCDD

0.1

 

PCB-126

0.1

 

1,2,3,6,7,8-HxCDD

0.1

 

PCB-169

0.03

 

1,2,3,7,8,9-HxCDD

0.1

 

Mono-ortho PCBs

 

 

1,2,3,4,6,7,8-HpCDD

0.01

 

PCB-105

0.00003

 

1,2,3,4,6,7,8,9-OCDD

0.0003

 

PCB-114

0.00003

 

PCDFs

 

 

PCB-118

0.00003

 

2,3,7,8-TCDF

0.1

 

PCB-123

0.00003

 

1,2,3,7,8-PeCDF

0.03

 

PCB-156

0.00003

 

2,3,4,7,8-PeCDF

0.3

 

PCB-157

0.00003

 

1,2,3,4,7,8-HxCDF

0.1

 

PCB-167

0.00003

 

1,2,3,6,7,8-HxCDF

0.1

 

PCB-189

0.00003

 

2,3,4,6,7,8-HxCDF

0.1

 

 

 

 

1,2,3,7,8,9-HxCDF

0.1

 

 

 

 

1,2,3,4,6,7,8-HpCDF

0.01

 

 

 

 

1,2,3,4,7,8,9-HpCDF

0.01

 

 

 

 

1,2,3,4,6,7,8,9-OCDF

0.0003

 

 

 

 

             
 

The EFSA Panel on Contaminants in the Food Chain (CONTAM) (EFSA, 2018) reviewed the data from experimental animal and epidemiological studies, and decided to base the human risk assessment on effects observed in humans, and to use animal data as supportive evidence.

The critical effect was on semen quality, following pre- and postnatal exposure.

The critical study showed a NOAEL of 7.0 pg WHO 2005-TEQ/g fat in blood sampled at age 9 years, based on PCDD/F-TEQ. No association was observed when including DL-PCB-TEQ.

Using toxicokinetic modelling, and taking into account the exposure from breastfeeding, and a twofold higher intake during childhood, it was estimated that daily exposure in adolescents and adults should be below 0.25 pg TEQ/kg bw/day. The Panel established a TWI of 2 pg TEQ/kg bw/week.

Dietary exposure

The most comprehensive estimates of dietary exposure have been provided by EFSA (EFSA, 2012, 2018). In their update of the monitoring of dioxins, and PCB levels in food and feed (EFSA, 2012), a total of 13,797 samples were assessed for dioxins and dioxin-like PCB (DL-PCB) and 19,181 samples for non-dioxin-like PCB (NDL-PCB). These samples were submitted between 1995 and 2010 by 26 European countries. At least one quantified congener of dioxins and DL-PCB was found in almost all samples, whereas at least one NDL-PCB indicator was quantified in 68.4 % of the feed, and 82.6 % of the food samples. Eels and fish liver, and derived products, contained the highest average contamination levels of both dioxins and PCB. Depending on the population group, defined as the combination of age class and the respective survey, average exposure to dioxins and DL-PCB was estimated to be between 0.57 and 2.54 pg TEQ WHO2005 /kg bw per day, and the 95th percentile between 1.2 and 9.9 pg TEQ WHO2005 /kg bw per day. Average exposure to NDL-PCB indicators was estimated to be between 4.3 and 25.7 ng/kg bw per day and the 95th percentile between 7.8 and 53.7 ng/kg bw per day.  Fish, meat and dairy products appeared to be the highest contributing food groups to dietary exposure. Although the concentrations measured in foods are all extremely low in absolute terms, they are relatively high when compared with the various tolerable daily (or weekly or monthly) intake values, that have been established by various organisations, including the WHO, in order to protect human health.

The TEF scheme does not currently cover other chemicals that have the same toxic mode of action, such as brominated and mixed halogenated analogues, and so may underestimate the true exposure to the totality of compounds that may contribute to this type of toxicity.

Global surveys of the occurrence of PCDD, PCDF and PCB in human milk have been performed by the WHO/UNEP (United Nations Environment Programme) since 1987. The three most recent surveys, from 2000 to 2010, have been reviewed (Van den Berg, 2016), and large global and regional differences were observed:

  • levels of PCDD and PCDF were highest in India and some European and African countries. PCB levels were highest in East and West Europe
  • a temporal downward trend for PCDD, PCDF and PCB was indicated
  • a risk-benefit assessment indicated that human milk levels of PCDD, PCDF and PCB were still significantly above those considered toxicologically safe. With respect to potential adverse health effects, a more dominant role of in utero exposure versus lactational exposure was indicated. If potential adverse effects were balanced against positive health aspects for (breastfed) infants, the advantages of breastfeeding far outweighed the possible disadvantages. 

'In the evaluation of the EFSA Panel on Contaminants in the Food Chain (CONTAM) (EFSA, 2018), the human chronic dietary exposure to PCDD/Fs and DL-PCBs was estimated using a data set containing:

  • 19,965 food samples with all 29 congeners determined (17 PCDD/Fs and 12 DL-PCBs)
  • 20,273 food samples with all 17 PCDD/F congeners determined (including samples with the 29 congeners)
  • 22,974 food samples with all 12 DL-PCB congeners determined (including samples with the 29 congeners)

With occurrence and consumption data from European countries the mean and P95 intake, respectively, of total TEQ by Adolescents, Adults, Elderly and Very Elderly varied between 2.1 to 10.5, and 5.3 to 30.4 pg TEQ/kg bw/week, implying a considerable exceedance of the TWI*. Toddlers and Other Children showed a higher exposure than older age groups, but this was accounted for when deriving the TWI. PCDD/Fs and DL-PCBs are well adsorbed and transferred to milk and eggs and accumulate in fatty tissues and liver. Transfer rates and bioconcentration factors were identified for various species.’                                                              *TWI is tolerable weekly intake.

‘Levels of the more relevant congeners in blood are in equilibrium with those in adipose tissue. At high exposure, PCDD/Fs and DL-PCBs can show higher lipid-based levels in liver than in adipose tissue. Most PCDD/Fs and DL-PCBs are poorly metabolised, but some hydroxylated metabolites have been identified.’

‘The main contributors to the mean dietary exposure for the age group Infants were Butter and Butter oil (contributing 6.1- 19.6%) and Fatty Fish (contributing 5.8 - 26.3%).

For Toddlers, the categories Fatty Fish (contributing 5.9 - 13.9%), Cheese (contributing 5.9 - 21.8%) and Livestock Meat (contributing 7.7 - 16.2%), were found to be the main sources of exposure.

Similarly, for the age groups of Other Children, Adolescents, Adults and Elderly the main contributors were Fatty Fish (up to 56% contribution), Unspecified Fish Meat (up to 53.4% contribution), Cheese (up to 21.8% contribution) and Livestock Meat (up to 33.8% contribution).’

The control of dioxins

Regulatory control

Regulatory limits for PCDD/F and PCB in foods have been set in Europe, under Commission Regulations (EC) Nos. 1881/2006, 1883/2006 and 152/2009, for food. Animal feed and additives are regulated under the ‘Feed Additives’ Commission Regulation (EC) No. 1831/2003 and ‘Undesirable substances in products intended for animal feed’ Commission Directive 2006/13/EC.  Official control for dioxins and PCBs in food and feed in Europe is managed through a network of the European Union Reference Laboratory (EU-RL), National Reference Laboratories (NRLs) and regional official control laboratories.  There are also regulations for analytical criteria, sampling, derogations and a number of other aspects that can be found on the website for the EU-RL for Dioxins and PCBs in Feed and Food (http://www.crl-freiburg.eu/dioxin/foodfeed.html).

In addition to maximum content, action thresholds have been set as early warning tools triggering investigations by Member States to investigate and control pollution sources.

Sampling and analysis methods

As with all chemical hazards, the effective control of dioxins requires efficient surveillance and monitoring programmes which, in turn, require efficient sampling and analysis methods. Furthermore, surveillance programmes require the careful selection of representative populations and samples.

The effective control of dioxins, from farm to fork, can be achieved by implementing Hazard Analysis and Critical Control Point (HACCP) programmes. (Ahmad et al, 2019)

It is also anticipated that blockchain systems will be increasingly used as a platform for HACCP programmes, ensuring the transparency and immutability of recorded activities throughout the supply chain, together with the traceability of the product (Sander et al, 2018).

Most analytical procedures for dioxins in foods and feeds use sophisticated techniques (EC No. 1883/2006 and EC No. 152/2009) such as gas chromatography/mass spectrometry (GCMS), coupled with extensive clean-up/concentration, for the required detection limits to be achieved. Gas chromatography in conjunction with high-resolution mass spectrometry, or quadrupole high-resolution time-of-flight mass spectrometry, are examples of the GCMS procedures employed (Špánik and Machyňáková, 2017). Such measurements are expensive although prices have been decreasing in recent years.

Yeast-based in vitro screens combined with high-performance thin-layer chromatography have also been employed for the analysis of dioxin-like compounds (Riegraf et al, 2019).

Sources and incidents

There are several examples whereby food has become contaminated by dioxins and PCBs and many of these are discussed by Hoogenboom et al (2015):

  1. A nationwide survey of dioxins in foodstuffs in the USA, in the late 1990s, detected elevated levels of dioxins in some samples of poultry meats. Animal feed was implicated as the likely source of contamination, due to incorporation of ball clay (an anti-caking agent) in the production of the feeds. Control centred upon initially changing certain production practices to minimise the issue and subsequently in providing appropriate general advice, to the feed industry, regarding suitable monitoring to prevent repetition.
  2. A programme of dioxin monitoring in foods, in Germany in the 1990s, initially showed a gradual decline which was followed by a gradual increase in certain products namely milk, butter and meats. Investigation implicated contaminated citrus pulp (a feed ingredient for ruminants) being supplied from South America. Once again, changes in production practices of the feed material eliminated the issue. This particular incident affected other European countries, as well as Germany, which highlighted the international aspect of the situation, as well as emphasising the need for regularly analysing large numbers of food samples for dioxins, in order to detect shifts in trends including seasonal variations.
  3. An outbreak of illness in poultry, in Belgium in 1999, was traced to animal feed contaminated with dioxins in recycled fat used in its manufacture. Farms in France, Holland and Spain had also used the contaminated material for their livestock. Products from poultry and pigs were affected but not those from cattle. Farms were quarantined, and contaminated products destroyed. More than 30 countries temporarily banned certain food imports from Belgium, until the issue was resolved.
  4. Ireland experienced trouble with elevated dioxin levels in some pork products, in 2008. Again, contaminated animal feed was implicated. The cause of the contamination was thought to be fuel oil used in the drying of the affected feed.

In all these cases, issues were initially raised by the finding of elevated dioxin levels in food products, during routine random testing.

Conclusions

PCDD/F and PCB are ubiquitous contaminants and are found at low levels in all the food we eat.  Concentrations are decreasing as a result of pollution control measures and increased food monitoring.  Some other classes of chemical exhibit similar toxic action and these are less well-controlled and monitored, meaning there is a possibility we may be underestimating the total exposure to this type of toxic chemical.

The industry needs to be vigilant at all times, and have sufficiently robust monitoring in place so that emerging issues can be resolved before products reach the marketplace.

Glossary of terms

PCDD               polychlorinated dibenzo-p-dioxin

PCDF               polychlorinated dibenzofuran

PCB                 polychlorinated biphenyl

DL-PCB            dioxin-like PCB

NDL-PCB          non-dioxin-like PCB

POP                 persistent organic pollutant

EU-RL               European Union Reference Laboratory

NRL                  National Reference Laboratory

WHO                World Health Organisation

TEQ                  toxic equivalence

TEF                  toxic equivalency factor

TWI                  tolerable weekly intake

AHR                 aryl hydrocarbon receptor

GCMS              gas chromatography - mass spectrometry

References and additional resources

2001 Stockholm Convention http://chm.pops.int/

PCB Elimination Network (PEN) https://bit.ly/309Dtpx

Ahmad S, Masood F, Khatoon K, Malik A. Risk Management of Chemical Hazards Arising During Food Manufacturing. Health and Safety Aspects of Food Processing Technologies [Internet]. Springer International Publishing; 2019;403–18. http://dx.doi.org/10.1007/978-3-030-24903-8_13

COC, Committee on Carcinogenicity in Food, Consumer Products and the Environment. Carcinogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. 2001 (July). http://www.iacoc.org.uk/statements/Tetra.htm

EFSA CONTAM Panel (EFSA Panel on Contaminants in the Food Chain), Knutsen HK, Alexander J, Barregard L, Bignami M, Bruschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hogstrand C, Nebbia CS, Oswald IP, Petersen A, Rose M, Roudot A-C, Schwerdtle T, Vleminckx C, Vollmer G, Wallace H, Furst P, Hakansson H, Halldorsson T, Lundebye A-K, Pohjanvirta R, Rylander L, Smith A, van Loveren H, Waalkens-Berendsen I, Zeilmaker M, Binaglia M, Gomez Ruiz J A, Horvath Z, Christoph E, Ciccolallo L, Ramos Bordajandi L, Steinkellner H and Hoogenboom LR, 2018. Scientific Opinion on the risk for animal and human health related to the presence of dioxins and dioxin-like PCBs in feed and food. EFSA Journal 2018;16(11):5333, 331 pp. https://doi.org/10.2903/j.efsa.2018.5333

 

European Food Safety Authority: Update of the monitoring of dioxins and PCBs levels in food and feed. EFSA Journal 2012; 10(7):2832. [82 pp.] doi:10.2903/j.efsa.2012.2832. www.efsa.europa.eu/efsajournal

Faqi AS, Dalsenter PR, Merker HJ, Chahoud I. Reproductive toxicity and tissue concentrations of low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin in male offspring rats exposed throughout pregnancy and lactation. Toxicology and Applied Pharmacology 1998, 150, 383–392. http://www.ncbi.nlm.nih.gov/pubmed/9653070

Fries GF. A review of the significance of animal food products as potential pathways of human exposures to dioxins. Journal of Animal Science. 1995, 73(6), 1629–1650.

http://www.ncbi.nlm.nih.gov/pubmed/7673057

Ron Hoogenboom, Wim Traag, Alwyn Fernandes and Martin Rose European developments following incidents with dioxins and PCBs in the food and feed chain. Food Control 50 670-683

Van den Berg M, Kypke K, Kotz A, Tritscher A, Lee SY, Magulova K, et al. WHO/UNEP global surveys of PCDDs, PCDFs, PCBs and DDTs in human milk and benefit–risk evaluation of breastfeeding. Archives of Toxicology [Internet]. Springer Science and Business Media LLC; 2016 Jul 20;91(1):83–96. http://dx.doi.org/10.1007/s00204-016-1802-z

Martin Van den Berg, Linda S. Birnbaum, Michael Denison, Mike De Vito, William Farland, Mark Feeley, Heidelore Fiedler, Helen Hakansson, Annika Hanberg, Laurie Haws, Martin Rose, Stephen Safe, Dieter Schrenk, Chiharu Tohyama, Angelika Tritscher, Jouko Tuomisto, Mats Tysklind, Nigel Walker and Richard E. Peterson  The 2005 World Health Organization Reevaluation of Human and Mammalian Toxic Equivalency Factors for Dioxins and Dioxin-Like Compounds  Toxicological Sciences  93 (2) 223-241 (2006)

Riegraf C, Reifferscheid G, Belkin S, Moscovici L, Shakibai D, Hollert H, et al. Combination of yeast-based in vitro screens with high-performance thin-layer chromatography as a novel tool for the detection of hormonal and dioxin-like compounds. Analytica Chimica Acta [Internet]. Elsevier BV; 2019 Nov;1081:218–30.http://dx.doi.org/10.1016/J.ACA.2019.07.018

Sander F, Semeijn J, Mahr D. The acceptance of blockchain technology in meat traceability and transparency. British Food Journal [Internet]. Emerald; 2018 Sep 3;120(9):2066–79. http://dx.doi.org/10.1108/BFJ-07-2017-0365

Špánik I, Machyňáková A. Recent applications of gas chromatography with high-resolution mass spectrometry. Journal of Separation Science [Internet]. Wiley; 2017 Dec 5;41(1):163–79. http://dx.doi.org/10.1002/jssc.201701016

Additional Resources

Kanan S, Samara F. Dioxins and furans: A review from chemical and environmental perspectives. Trends in Environmental Analytical Chemistry. 2018 Jan 1;17:1-3.

Weber R, Herold C, Hollert H, Kamphues J, Blepp M, Ballschmiter K. Reviewing the relevance of dioxin and PCB sources for food from animal origin and the need for their inventory, control and management. Environmental Sciences Europe. 2018 Dec 1;30(1):42.

Institute of Food Science & Technology has authorised the publication of the following updated Information Statement on Dioxins and Dioxin-like Compounds in Foods and Feeds, peer-reviewed by professional members of IFST and approved by the IFST Scientific Committee. 

IFST Scientific Committee is grateful to Professor Raymond Coker for valuable suggestions for this Information Statement.

This information statement is dated October 2020, replacing that of January 2013. 

The Institute takes every possible care in compiling, preparing and issuing the information contained in IFST Information Statements, but can accept no liability whatsoever in connection with them. Nothing in them should be construed as absolving anyone from complying with legal requirements. They are provided for general information and guidance and to express expert professional interpretation and opinion, on important food-related issues.