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Furan, 2-methylfuran and 3-methylfuran in Selected Foods - April 1, 2013 to March 31, 2018

Food chemistry – Targeted surveys – Final report

Summary

Targeted surveys provide information on potential food hazards and enhance the Canadian Food Inspection Agency's (CFIA's) routine monitoring programs. These surveys provide evidence regarding the safety of the food supply, identify potential emerging hazards, and contribute new information and data to food categories where it may be limited or non-existent. They are often used by the CFIA to focus surveillance on potential areas of higher risk. Surveys can also help to identify trends and provide information about how industry complies with Canadian regulations.

Furan is a chemical that can unintentionally form in foods that undergo thermal treatment such as canningFootnote 1. Precursors to furan that are often present in food include ascorbic acid, polyunsaturated fatty acids, amino acids and sugarsFootnote 1Footnote 2Footnote 3. This compound occasionally coexists with 2-methylfuran and 3-methylfuran. In this report, the term 'furans' refers to the sum of furan, 2-methylfuran and 3-methylfuran, whereas 'furan' refers only to the furan compound. The term "analogue" refers to compounds which have similar but slightly different structures; it is sometimes used in this report to refer to the 3 forms of furan. It should be noted that the furans in this survey are not related to chlorinated dibenzofurans, the environmental contaminants which are often also referred to as "furans".

Furan may pose a health risk to the consumer, as the International Agency for Research on Cancer (IARC) has classified it as 'possibly carcinogenic to humans'Footnote 4. Additionally, 2-methylfuran and 3-methylfuran have been shown to have a similar toxicity to furanFootnote 5. Although preliminary estimates for consumer exposure are well below what would cause harmful effects, limited information is available concerning furan levels in food. Therefore, the goal of this survey was to generate further baseline surveillance data on the presence and levels of furan, 2-methylfuran and 3-methylfuran in selected heat treated foods available on the Canadian retail market.

A total of 945 samples were collected from retail stores in 6 cities across Canada. The samples collected included alcoholic beverages, beer, breakfast cereals, potato chips, coffee, infant foods, processed fruits and vegetables, sauces and soup. Furans were detected in 83% of the survey samples and levels ranged from 0.55 ppb (parts per billion) to nearly 284000 ppb. The highest average concentrations of furans were found in coffee. Of the samples studied, 19% (184) contained only 1 of the 3; 2 of the 3 were present in 29% (273 samples) and all 3 furans were detected in 329 samples (35%). The results from this survey were comparable to those found in international surveys and a variety of scientific studies.

The levels of furans observed in this survey were evaluated by Health Canada who determined that none of the samples would pose an unacceptable human health concern, therefore there were no recalls resulting from this survey.

What are targeted surveys

Targeted surveys are used by the CFIA to focus its surveillance activities on areas of highest health risk. The information gained from these surveys provides support for the allocation and prioritization of the agency's activities to areas of greater concern. Originally started as a project under the Food Safety Action Plan (FSAP), targeted surveys have been embedded in the CFIA's regular surveillance activities since 2013. Targeted surveys are a valuable tool for generating information on certain hazards in foods, identifying and characterizing new and emerging hazards, informing trend analysis, prompting and refining health risk assessments, highlighting potential contamination issues, as well as assessing and promoting compliance with Canadian regulations.

Food safety is a shared responsibility. The CFIA works with federal, provincial, territorial and municipal governments and provides regulatory oversight of the food industry to promote safe handling of foods throughout the food production chain. The food industry and retail sectors in Canada are responsible for the food they produce and sell, while individual consumers are responsible for the safe handling of the food they have in their possession.

Why did we conduct this survey

The main objectives of this targeted survey were to generate further baseline surveillance data on the level of furan, 2-methylfuran and 3-methylfuran in domestic and imported products on the Canadian retail market, and to compare the prevalence of furans in foods targeted in this survey with that of similar products in international surveys and to the scientific literature.

Furan may pose a health risk to consumers since the IARC has classified it as 'possibly carcinogenic to humans'Footnote 4. Furan can sometimes form in foods that undergo heat treatments, particularly in foods that contain its precursors such as ascorbic acid, polyunsaturated fatty acids, amino acids and sugarsFootnote 1Footnote 2Footnote 3. In some foods, 2-methylfuran and 3-methylfuran can also form, which have a similar toxicity to furanFootnote 5. Because thermal treatments are widely used for manufacturing shelf-stable food, it is important to establish data on the prevalence of furan, 2-methylfuran and 3-methylfuran in food available on the Canadian retail market.

Maximum Residue Limits (MRLs) for furans levels have not yet been established, as the toxicity of furans in humans is not well known. The U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have studied furan levels in a variety of commoditiesFootnote 6Footnote 7, but limited data is available concerning 2- and 3-methylfuran levels. This survey was initiated in consultation with Health Canada to establish further baseline surveillance data to compliment and expand upon the data collected by other agenciesFootnote 1.

What did we sample

These products were selected as they undergo heat treatment (frying, baking, pasteurisation) which can result in the formation of furans. In this multi-year survey, a variety of domestic and imported products from the following categories were tested including: alcoholic beverages (brandy, gin, rum, tequila, vodka, whiskey, Polish liqueur, cherry brandy, ouzo, sugar cane spirits), beer, breakfast cereals, potato chips, coffee, infant foods, processed fruits and vegetables, sauces and soup. Products were sampled between April 1 and March 31st for the following survey years: 2013-14, 2014-15, 2015-16, 2016-17, and 2017-18. Samples of products were collected from local/regional retail locations located in 6 major cities across Canada. These cities encompassed 4 Canadian geographical areas:

  • Atlantic (Halifax)
  • Quebec (Montreal)
  • Ontario (Toronto and Ottawa)
  • West (Vancouver and Calgary)

The number of samples collected from these cities was in proportion to the relative population of the respective areas. The samples surveyed originated from 46 countries and included domestic products.

Table 1. Distribution of samples based on product type and origin
Product type Number of domestic samples Number of imported samples Number of samples of unspecified Table Note a origin Total number of samples
Alcoholic beverages 65 79 6 150
Beers 14 31 0 45
Breakfast Cereals 51 89 50 190
Coffees 39 43 27 109
Infant Foods 20 53 26 99
Potato Chips 44 25 26 95
Processed fruits and vegetables 47 106 11 164
Sauces 15 16 12 43
Soups 33 10 7 50
Total 328 452 165 945

How were samples analyzed and assessed

Samples were analyzed by an ISO/IEC 17025 accredited food testing laboratory under contract with the Government of Canada. The furan level reported per sample is the sum of the levels of furan, 2-methylfuran and 3-methylfuran, where detected. The results are based on the food products as sold and not necessarily as they would be consumed.

In the absence of established tolerances or standards for furans in foods, elevated levels of in specific foods may be assessed by Health Canada on a case-by-case basis using the most current scientific data available.

What were the survey results

Of the 945 samples tested, 786 (83%) had detected levels of furans (sum of detected levels of furan, 2-methylfuran, and 3-methylfuran). Furan was detected in 755 samples, 2-methylfuran was detected in 588 samples, and 3-methylfuran was detected in 371 samples. The average concentrations decreased in the order: 2-methylfuran (2188 ppb) > furan (506 ppb) > 3-methylfuran (113 ppb). Of the samples tested, 19% (184) contained 1 of the 3 compounds; 2 of the 3 furans were present in 273 samples (29%), and all 3 compounds were found in 35% (329 samples). Table 2 shows that the detection rate of furans varied greatly between product types. Among all product types included in this survey, the average concentration was highest in coffee and lowest in beer.

Table 2. Summary of targeted survey furan results in selected foods by product type in ppb.
Product type Number of samples Number of samples (%) with detected levels Minimum (ppb) Maximum (ppb) Average Table Note b (ppb)
Alcoholic beverages 150 45 (30) 0.55 9.9 3.5
Beer 45 30 (67) 0.7 9.8 1.0
Breakfast cereals 190 173 (91) 2.5 707 46
Coffee 109 109 (100) 2.0 283675 24102
Infant foods 99 97 (98) 1.5 232 51
Potato chips 95 83 (87) 2.6 341 20
Processed fruits and vegetables 164 157 (96) 0.64 204 18
Sauces 43 42 (98) 8.4 143 42
Soup 50 50 (100) 1.0 658 73
Total 945 786 (83) 0.55 283675 3372

Alcoholic beverages and beer

There were 10 types of alcoholic beverages sampled. Furans were not detected in samples of brandy, sugar cane spirits, or Polish liqueur. Tequila was associated with the highest detection rate and the highest average concentration of furans (5.0 ppb). See Table 1 in Appendix A for a more detailed breakdown of furan levels by type of alcoholic beverage.

Furans were detected in 30 out of 45 beer samples (67%) tested. There was no trend between type of beer and furan levels.

Breakfast cereals

Most (91%) of breakfast cereals had detectable levels of furans. The detection rate was 86% (83 out of 96 samples) in cereals targeted to adults and 96% (90 out of 94 samples) in cereals targeted at children. Levels of furans ranged from 2.5 ppb to 192 ppb in cereals for adults and from 3.6 ppb to 707 ppb in cereals for children. The average furan levels were 31 ppb and 59 ppb for cereals for adults and for children, respectively.

Detection rates were highest in corn and rice cereals (100%) and lowest in oat-based cereals (87%). Average furan levels were highest in corn-based cereals (63 ppb) and lowest in oat-based cereals (30 ppb). See Table 2 in Appendix A for a more detailed breakdown of furan levels by grain type.

Coffee

All samples of coffee (ready-to-drink shelf-stable beverages, coffee beans, ground coffee and instant coffee) contained detectable levels of furans. Coffee products were associated with the highest detection rates, the highest observed levels, and the highest average level of furans for the products tested in this survey. The highest average level was observed in coffee beans (38 812 ppb) and the lowest in beverages (111 ppb). See Table 3 in Appendix A for a more detailed breakdown of furan levels by type of coffee product.

Infant foods

Infant foods tested in this survey included: fruit purees, fruit and vegetable purees, vegetable purees and meals for infants/toddlers. Of the 99 infant food products tested, all but 2 samples contained furans. The average level of furans was highest in vegetable purees (89 ppb) and lowest in fruit purees (11 ppb). See Table 4 in Appendix A for a more detailed breakdown of furan levels by type of infant food.

Potato chips and Processed fruits and vegetables (PFV)

Most samples of potato chips (83 out of 95 or 87%) contained detectable levels of furans. The detection rate and furan levels were similar to other processed fruits and vegetables.

There were 22 different fruits and vegetables captured in this product type, with mixed fruits, mixed vegetables, beans and peaches making up 67% of the samples. The detection rate was 100% for 17/22 types of fruits and vegetables; the detection rate decreased in the order: mixed fruits (97%) > mixed vegetables (94%) > peach (91%) > pineapple (88%) > pear (80%). The average furan level was highest in sweet potato (137 ppb) and lowest in lychee (1.0 ppb). See Table 5 in Appendix A for a more detailed breakdown of furan levels by type of fruit or vegetable.

Sauces

Only Barbeque (BBQ) and steak sauces were examined as these undergo heat treatment during production. Furans were detected in 42 out of 43 samples The lowest (8.4 ppb) and highest furan levels were detected in BBQ sauces.

Soups

All 50 soup (including broths, vegetable soups, meat-containing soups, poultry-containing soups) samples had detectable levels of furans. The lowest furan level was detected in chicken broth (1.02 ppb) and the highest level was detected in rib + vegetable soup (658 ppb).

What do the survey results mean

For all product types, furan levels found in this survey were comparable to the data in the scientific literatureFootnote 6Footnote 7Footnote 8Footnote 9Footnote 10Footnote 11Footnote 12Footnote 13Footnote 14Footnote 15Footnote 16Footnote 17Footnote 18. Table 3 focuses on the levels for furan found, as limited data is available concerning 2- and 3-methylfuran levels in foods and therefore no comparison on the presence of 2- and 3-methylfuran could be made. Where feasible, total furan levels are reported.

The detection rates in the CFIA surveys were within the range of those reported for the scientific literature, except for alcoholic beverages. There is little data available on the furan levels in gin, tequila, and vodka. The maximum furan levels in the CFIA surveys were within the range reported for the literature, except for alcoholic beverages, potato chips, coffee and PFV where the levels are higher in the CFIA surveys. The average furan levels in the CFIA surveys fall within the range reported in other studies, except for coffee, infant food, PFV and soup where the average level in the CFIA surveys are higher. In most of the cases, this may be due to larger sample size and more targeted product selection.

Table 3. Minimum, maximum and average concentration of furan in selected foods in ppb
Product type Study Number of samples Number (%) positive samples Minimum (ppb) Maximum (ppb) Average (ppb)
Alcoholic beverages CFIA, 2017 50 14 (28) 0.55 9.9 3.5 Table Note c
Alcoholic beverages CFIA, 2016 50 20 (40) 0.7 9.8 1.0 Table Note c
Alcoholic beverages CFIA, 2015 50 11 (22) 0.55 9.9 3.5 Table Note c
Alcoholic beverages Canada, Goldberg et al., 1999 8 not specified 1.50 4.44 2.97 Table Note c Whisky, not detected in rum
Beer CFIA, 2017 15 8 (53) 1.8 9.8 4.8 Table Note c
Beer CFIA, 2016 15 13 (87) 0.70 6.5 2.0 Table Note c
Beer EFSA, 2011 102 Not specified Not specified 28 3.3 Table Note c
Beer Taiwan, Liu et al., 2010 5 5 (100) 3.0 20.0 11.5 Table Note c
Beer EFSA, 2009 5 Not specified <2.4 2.9 Not specified
Beer US FDA, 2009 8 4 (50) 0.8 4.4 1.9 Table Note c
Breakfast cereals CFIA, 2017 50 9 (60) 1.5 5.2 2.9 Table Note c
Breakfast cereals CFIA, 2016 50 47 (94) 6.6 160 41 Table Note c
Breakfast cereals CFIA, 2015 50 49 (98) 2.5 192 36 Table Note c
Breakfast cereals CFIA, 2014 20 43 (86) 3.1 707 66 Table Note c
Breakfast cereals CFIA, 2013 20 16 (80) 3.7 158 36 Table Note c
Breakfast cereals Czech, Fromberg et al., 2014 11 Not specified < 2.4 387 57.4
Breakfast cereals Brazil, Arisseto et al., 2012 6 6 (100) 11.8 23.9 18.8
Breakfast cereals Taiwan, Liu, 2010 8 8 (100) 12.7 65.3 34.3
Breakfast cereals EFSA, 2009 11 8 (73) <2.4 387 79
Breakfast cereals US FDA, 2009 25 16 (64) 2.3 47.5 18.4
Chips - Potato CFIA, 2017 25 18 (72) 5.0 31 17 Table Note c
Chips - Potato CFIA, 2016 25 25 (100) 2.8 29 11 Table Note c
Chips - Potato CFIA, 2015 25 21 (84) 2.6 341 37 Table Note c
Chips - Potato CFIA, 2014 10 9 (90) 2.6 24 14 Table Note c
Chips - Potato CFIA, 2013 10 10 (100) 2.7 82 16 Table Note c
Chips - Potato Chile, Mariotti-Celis et al., 2017 3 3 (100) 173 234 200
Chips - Potato Czech, Fromberg et al., 2014 9 Not specified < 2.4 91 24.3
Chips - Potato EFSA, 2009 1 0 (0) <2.4 <2.4 <2.4
Coffee CFIA, 2017 25 25 (100) 14 57697 13581 Table Note c
Coffee CFIA, 2016 25 25 (100) 10 47416 17564 Table Note c
Coffee CFIA, 2015 25 25 (100) 26 283675 56237 Table Note c
Coffee CFIA, 2014 15 15 (100) 66 152396 22536 Table Note c
Coffee CFIA, 2013 19 19 (100) 52 21040 5505 Table Note c
Coffee Canada, Becalski et al., 2016 79 79 (100) 32.13 16 422 4404
Coffee Brazil, Arisseto et al., 2012 79 73 (92) 15 400 5021 1172
Coffee EFSA, 2011 934 Not specified Not specified 11000 1682
Coffee (brewed) Spain, Altaki et al., 2011 44 44 (100) 13 146 49
Coffee Taiwan, Liu et al., 2010 10 10 (100) 35.4 150.0 66.9
Coffee EFSA, 2009 17 14 (82) 122 1966 884
Coffee US FDA, 2009 14 10 (71) 4.8 84.2 38.6
Infant foods CFIA, 2017 22 22 (100) 10 232 106 Table Note c
Infant foods CFIA, 2016 24 24 (100) 2.1 138 31 Table Note c
Infant foods CFIA, 2015 24 23 (96) 1.5 114 33 Table Note c
Infant foods CFIA, 2014 20 19 (95) 1.9 172 46 Table Note c
Infant foods CFIA, 2013 9 9 (100) 3.4 92 32 Table Note c
Infant foods Czech, Fromberg et al., 2014 5 Not specified < 2.4 45 17.8
Infant foods EFSA, 2011 1617 Not specified Not specified 233 31
Infant foods S. Korea, Kim et al., 2010 10 10 (100) 6.15 102.48 29.93
Infant foods Taiwan, Liu et al., 2010 8 8 (100) 4.3 124.1 31.4
Infant foods Germany, Lachenmeier et al., 2009 214 176 (82) 2-5 >50 24.5
Infant foods EFSA, 2009 37 23 (62) <2.4 83 8.0
Infant foods US FDA, 2009 148 143 (97) 1.3 112 35.0
PFV CFIA, 2017 43 43 (100) 1.4 204 34 Table Note c
PFV CFIA, 2016 41 41 (100) 0.97 65 11 Table Note c
PFV CFIA, 2015 41 38 (93) 0.64 120 11 Table Note c
PFV CFIA, 2014 20 18 (90) 1.1 55 15 Table Note c
PFV CFIA, 2013 19 17 (89) 1.2 41 9.2 Table Note c
PFV Czech, Fromberg et al., 2014 18 Not specified < 2.4 12 3.8
PFV Brazil, Arisseto et al., 2012 70 42 (60) <2.4 16.1 5.1
PFV EFSA, 2011 391 Not specified Not specified 80 7.3
PFV S. Korea, Kim et al., 2010 10 10 (100) 3.08 58.30 17.50
PFV Taiwan, Liu et al., 2010 5 5 (100) 3.4 15.2 11.7
PFV EFSA, 2009 1 1(100) 102 102 N/A Table Note d
PFV US FDA, 2009 76 73 (96) 0.5 122 21.7
Sauces CFIA, 2017 10 10 (100) 20 121 64 Table Note c
Sauces CFIA, 2016 10 10 (100) 8.4 143 47 Table Note c
Sauces CFIA, 2015 10 9 (90) 12 72 35 Table Note c
Sauces CFIA, 2014 5 5 (100) 14 29 18 Table Note c
Sauces CFIA, 2013 8 8 (100) 13 68 32 Table Note c
Sauces EFSA, 2011 270 Not specified Not specified 175 8.3
Sauces Taiwan, Liu et al., 2010 2 2 (100) 21.7 123 72.4
Sauces US FDA, 2009 3 3 (100) 13.5 28 19
Soup CFIA, 2017 10 10 (100) 1.0 174 80 Table Note c
Soup CFIA, 2016 10 10 (100) 2.2 101 55 Table Note c
Soup CFIA, 2015 10 10 (100) 2.4 658 109
Soup CFIA, 2014 10 10 (100) 12 187 72 Table Note c
Soup CFIA, 2013 10 10 (100) 2.2 101 47 Table Note c
Soup EFSA, 2011 270 Not specified Not specified 225 23
Soup S. Korea, Kim et al., 2010 5 5 (100) 8.99 36.20 18.54
Soup EFSA, 2009 12 11 (92) <2.4 47 29.4
Soup US FDA, 2009 36 36 (100) 6.7 125 36.6

Health Canada's Bureau of Chemical Safety determined the levels of furan, 2-methylfuran and 3-methylfuran in food observed in this survey are not expected to pose a concern to human health; therefore no follow-up actions were required.