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Perchlorate in Plant-Based Foods: a Follow-up

Report from a day in the lab

Dr. Ingrid Kaufmann-Horlacher, Ellen Scherbaum

 

Perchlorate is an unwanted substance in food that causes reversible inhibition of iodine absorption in the thyroid. No maximum limit has thus far been established for this contaminant in food. In 2015 the Standing Committee for Plants, Animals, Food and Feed (SC PAFF) approved valid reference values based on recommendations by the EU-Commission.[1] Products that do not exceed these reference values are marketable in all EU member states.

 

Photo.

 

Since CVUAS began investigating perchlorate in 2013[2, 3], our data does not show any significant change in the overall situation. Perchlorate was detected in 24 % of all the analyzed samples from 2017 and 2018 (limit of determination: 0.005 mg/kg). This rate was significantly higher in vegetables, especially in leafy vegetables such as spinach, rocket salad, fresh herbs and kale. Individual samples in this group revealed concentration levels as high as 2.4 mg/kg. In contrast to the situation for pesticides in fruits and vegetables, the levels of perchlorate found in both conventionally and organically grown vegetables are comparable. The country of origin appears to be even less significant than thetype of product; samples containing detectable levels of perchlorate come from a wide range of countries. The establishment of a maximum level for perchlorate in food has been long discussed, and there is currently a recommendation for maximum levels within the framework of contamination regulations. This report addresses these new levels, with a look at the amounts measured in 2017 and 2018.

 

Overview

Over the past two years of 2017 and 2018 a total of 5,118 plant-based samples were analyzed at CVUA Stuttgart for the presence of perchlorate.[4] These comprised mostly fresh fruits and vegetables, but also deep-frozen and, in smaller amounts, processed foods. Perchlorate was detected at levels at or above 0.005 mg/kg in 24 % of all the analyzed samples.

 

Infobox

Perchlorate

Perchlorates are the salts of perchloric acid. They are easily soluble in water and are relatively stable. Perchlorates are persistent in the environment and are considered ubiquitous environment contaminants. Their occurrence can be caused either anthropogenically (by humans) or naturally, from the use, e.g. of natural fertilizers such as Chile saltpeter, from industrial emissions, from the natural formation of perchlorate in the atmosphere and surface waters, and from its formation during the disinfection of water with sodium hypochlorite.

 
Plants take in perchlorate mainly via their roots; therefore, earlier applications of fertilizers containing natural sources of perchlorate such as Chile saltpeter or exposure to soil or water contaminated with perchlorate are likely causes for the presence of perchlorate in plant-based foods.

 

Perchlorate reversibly inhibits the absorption of iodine in the thyroid. The European Food Safety Authority (EFSA) published a new reference dose for the long-term risk assessment in 2014 (updated in 2015). The tolerable daily intake (TDI) was set at 0.0003 mg/kg bodyweight and day.[5] For a person weighing 70 kg, this means a tolerable daily intake of 0.021 mg. The derivation of an acute reference dose (ARfD) was not seen by EFSA to be necessary. This assessment was agreed to by the Federal Institute for Risk Assessment (BfR).[6]

 

The rate for fresh and deep-frozen vegetables was even higher, at 37 %, where 944 out of 2,587 product samples were detected with perchlorate at levels at or above 0.005 mg/kg. Levels above 0.05 mg/kg were found in 60 samples (2.3 %), and levels above 0.1 mg/kg were detected in 19 samples (0.7 %). Leafy vegetables were particularly affected, especially kale, spinach, rocket salad and fresh herbs. The amounts, however, were in the lower area of detection of 0.005 mg/kg. The highest level was detected in a sample of German-grown kale, at 2.4 mg/kg, followed by fresh Swiss chard, also from Germany, at 0.88 mg/kg, and fresh dill, of unknown origin, at 0.48 mg/kg. Table 1 presents an overview of those samples containing high levels of perchlorate.

 

Table 1: Samples with High Levels of Perchlorate
Fresh Products
mg/kg
Dried Products
mg/kg
Kale 2.4 Moringa Tea 2.2
Swiss Chard 0.88 Oregano, Moringa Leaf Powder 1.7
Dill 0.48 Moringa Tea, Moringa Leaf Powder 1.6
Kale, deep frozen 0.38 Moringa Leaf Powder 1.5
Italian Broccoli 0.27 Spearmint Tea 1.4
Lamb’s Lettuce 0.27 Oolong Tea, Peppermint Tea 1.3
Rocket Salad 0.20 2 x Moringa Leaf Powder 1.2
Spinach 0.18 Peppermint Tea 1.1
Cress, Broccoli 0.17 Moringa Leaf Powder 1
Celery, Parsley leaves 0.16 Moringa Leaf Powder 0.99
Brazil nut 0.15 Moringa Tea 0.98
Basil, 2 x Spinach 0.14 Moringa Leaf Powder 0.91
2 x Basil, Bell Pepper 0.13 Spice 0.86
Cress, Spinach 0.12 Rooibos Tea 0.79
Radicchio, Dill, Bell Pepper 0.11 Spice 0.59

 

For leaf lettuce, the rate of contamination with perchlorate was 41 %; for spinach and rocket salad it was even greater than 90 %. More than three-quarters of all the fresh herb and kale samples were also affected (78 % and 86 % respectively). Much lower rates of perchlorate contamination were found for fruits, sprout and root vegetables, potatoes, cereals, legumes, oil seeds and mushrooms. An exception was with citrus fruits, 29 % of which contained amounts at or above the limit of determination. Except for two samples, these amounts were under 0.05 mg/kg. Only 6 % of the potatoes, including sweet potatoes and topinambur (Jerusalem artichokes), contained levels at or above the limit of determination;  these had less than 0.05 mg/kg, with the exception of one sample of new potatoes from Egypt containing 0.094 mg/kg.

 

Dried food products such as herbal teas, leafy herbs, vegetable powder and nutritional supplements based on Moringa oleifera leaves contained up to 2.2 mg/kg perchlorate. The drying process must be taken into consideration, however, because this intensifies the contamination; the levels in the fresh state of the plants are significantly lower.

Only one of the 25 samples of ready-to-eat vegetable and fruit preparations for babies and small children contained an amount of 0.005 mg/kg. None of the seven partially ready-to-eat cereal-porridge or cereal-based powder samples for babies and small children was detected with any perchlorate. Among the total of 32 samples for this consumer group, none exceeded the value of 0.01 mg/kg.


An overview of the quantities detected in all of the analyzed samples of the last two years is depicted in Table 2, itemized by product group.

 

Table 2: Overview of Perchlorate Amounts Detected in Plant-Based Foods in 2017 and 2018
Product Group
No. of Samples
Samples Containing Perchlorate
≥ 0.005 mg/kg
%
Median Value
mg/kg
Average
mg/kg
Maximum
mg/kg
Berries 546 21 4 0.010   0.018
Pome Fruit 254  -        
Stone Fruit 365 13 4 0.015   0.044
Citrus Fruit 280 81 29 0.014 0.010 0.067
Exotic Fruit 342 34 10 0.014 0.011 0.059
Fruit Juice 39  -        
Dried Fruit 43 5 12 0.013   0.02
Leafy Vegetables (excluding kale, lettuce, spinach, rocket salat, and fresh/deep frozen herbs) 224 55 25 0.043 0.011 0.88
Kale, fresh and deep frozen 42 36 86 0.103 0.028 2.4
Leafy lettuce 386 160 41 0.019 0.010 0.27
Spinach, fresh and deep frozen 63 58 92 0.037 0.023 0.18
Rocket Salad 39 37 95 0.037 0.026 0.2
Herbs, fresh and deep frozen 204 160 78 0.035 0.017 0.48
Fruit Vegetables, excluding cucurbits 675 189 28 0.011 0.008 0.13
Cucurbits 284 131 46 0.015 0.010 0.077
Sprout Vegetables 336 54 16 0.013 0.008 0.17
Root Vegetables 237 59 25 0.009   0.023
Potatoes, Sweet Potatoes, Topinambur 97 6 6 0.036 0.035 0.094
Dried vegetables, dried herbs, spices 69 58 84 0.25 0.17 1.7
Herbal and Fruit Teas 37 36 97 0.37 0.14 2.2
Tea 21 11 52 0.31 0.25 1.3
Grains (cereals) and Pseudo Grains 137 6 4 0.017   0.026
Legumes, Oil Seeds, Nuts, Soy 168 8 5 0.032 0.016 0.15
Mushrooms, fresh and deep frozen 94        
Mushrooms, dried 19 6 32 0.087   0.38
Cereal porridge for babies and small children 7        
Baby food, ready-to-eat   25 1 4 0.005   0.005
Wine and Wine products 73 6 8 0.008   0.014
Other 12 8 62 0.72   1.7
Total 5118 1238 24     2.4

 

Since especially leafy vegetables and, to a lesser extent, fruiting vegetables were frequently affected and detected with higher amounts, this product group was more thoroughly assessed. Table 4 presents, among others, the results for selected product groups, itemized by concentration levels.

 

Infobox

Contaminants

Contaminants are unwanted substances that are not intentionally added to food, but are nevertheless present as a result of either environmental pollution or as residues from, e.g. the extraction, production, processing, or preparation of the food. Many substances end up in the environment as a result of their application in industry (e.g. PCBs, heavy metals) or as unintended by-products (e.g. dioxins). Depending on their properties, they can land in or on food or even become concentrated. Other unwanted substances occur when food is not properly manufactured or treated (e.g. PACs, nitrosamines) or the growth / harvest conditions are not appropriate (e.g. PACs, nitrosamines, fungal and bacterial toxins).

 

Contaminants are subject to a general minimizing requirement, specified in Regulation (EEC) No. 315/93. Contaminant levels in food shall be kept in line with the ALARA Principle: As Low As Reasonably Achievable. Food containing  contaminants in amounts that are unacceptable from a public health view shall not be placed on the market. The maximum amounts provided by Regulation (EC) No. 1881/2006 and the National Contaminant Regulation from 19 March, 2010 cover those contaminants that pose a health risk to consumers. There is currently no binding maximum level for perchlorate; however, this issue is being discussed within EU bodies, whether to be included under Regulation (EC) No. 1881/2006.

 

How are Perchlorate Amounts in Food to be Legally Assessed?

As a contaminant, perchlorate falls under the contaminant law. For the preventative protection of consumers, Regulation (EC) No. 315/93 requires the general minimizing of foreign substances in food in accordance with the ALARA principle. Legally binding maximum levels for perchlorate in food have not yet been established. However, the Standing Committee for Plants, Animals, Food and Feed (SC PAFF) agreed to a recommendation made by the EU Commission by which, starting 1 July 2015, foods containing amounts under the reference values[1] presented in Table 3 would be marketable in all member states.

 

Table 3: Reference Values for Perchlorate in Foods Established by Standing Committee SC PAFF, 2015 [1]
Product
Reference Value 2015*
Fruit and Vegetables 0.1 mg/kg
With exception of: Cucurbits and Leafy Vegetables 0.2 mg/kg
With exception of: Celery and Spinach from greenhouse or under plastic 0.5 mg/kg
Herbs, Rocket Salad, Head Lettuce, Lettuce from greenhouse or under plastic 1.0 mg/kg
Dried Spices, Dried Hops 0.5 mg/kg
Tea (Camillia Sinensis) 0.75 mg/kg
Herbal and Fruit Tea 0.75 mg/kg
Food for babies and small children / ready-to-eat 0.02 mg/kg
Other foods 0.05 mg/kg

*Processing factors are to be applied where necessary. The reference values are valid for the edible parts. Products grown in a greenhouse or under plastic should be so labeled; if not, the reference values for products grown outside are to be used.

 

EU bodies have been discussing the establishment of maximum levels for perchlorate in certain foods within the framework of Regulation (EC) No. 1881/2006 for a long time. In the meantime, the EU Commission has made a concrete proposal that encompasses maximum levels for specific products or product groups. The recommended maximum amounts are, in some cases, lower than previously valid reference values. A general maximum level for “other” foods (the current reference value is 0.05 mg/kg) has not been provided. The provision used thus far to apply the higher value of 0.5 mg/kg instead of 0.1 mg/kg for spinach, rocket salad and herbs that have been grown in a greenhouse or under plastic shall no longer be used in the future. It is not required to state the conditions of cultivation, because this information is usually not available to the monitoring officials. A maximum level of 0.5 mg/kg will now be recommended for spinach, rocket salad and herbs, regardless of the method of cultivation.
Table 4 shows the currently discussed maximum levels applied to our analytical results from 2017 and 2018. An overview of all the analyzed samples can be found in Annex 1.


The percentage of samples with a measured value above the recommended maximum were in a very low, single-digit range (0-1.3 %), with the exception of dried products. That means almost all analyzed leafy and fruiting vegetable samples contained levels of perchlorate lower than the recommended maximums. When measurement uncertainty is taken into consideration, only two out of a total of 959 (0.2 %) samples of fruiting vegetables and just five out of a total of 958 (0.5 %) samples of leafy vegetables would have exceeded the currently discussed maximum levels with certainty. Among the vegetables that are often contaminated with perchlorate, such as spinach, rocket salad and fresh herbs, the percentage of samples containing levels exceeding the recommended maximums was 0 %. That means, all of the total 306 samples of spinach, rocket and herbs analyzed in 2017 and 2018  contained measured values for perchlorate that were lower than the recommended maximums.

 

Table 4: Amounts of Perchlorate in Plant-Based Foods from 2017/18 and the Recommended Maximum Levels – Excerpt (detailed amounts are listed in Annex 1)
Product Group
No. Samples
Samples Containing Perchlorate
Currently Discussed Maximum Levels (ML)  for Perchlorate in Foods
≥ 0.005 mg/kg
>0.01
mg/kg
>0.05
mg/kg
>0.1
mg/kg
>0.2
mg/kg
>0.5
mg/kg
ML mg/kg
> ML in %
Individual
Findings* > ML
Recommendation
Citrus Fruit 280 81 39 2       0.05 0.7 % 0.067 Grapefruit / ES
0.056 Pomelo / China
Exotic Fruit 342 34 20 1       0.05 0.3 % 0.059 Pomegranate / Peru
Leafy Vegetables, excluding kale, lettuce, spinach, rocket salad and fresh herbs, incl. deep frozen 224 55 28 8 3 2 1 0.1 1.3 % 0.88 Swiss chard / DE**
0.27 Italian broccoli / IT**
0.16 Celery / DE
Kale, fresh and deep frozen 42 36 29 6 2 2 1 0.1 0.9 % 2.4 Kale / DE**
0.38 Kale**
Leaf Lettuce 386 160 75 12 4 1   0.1 1.0 % 0.27 Lamb’s lettuce / DE**
0.17 Cress / NL
0.12 Cress / NL
0.11 Radicchio
Spinach, fresh and deep frozen 63 58 50 12 4     0.5 0 %  
Rocket Salad 39 37 28 10 1     0.5 0 %  
Herbs, fresh and deep frozen 204 160 112 30 9 2   0.5 0 %  
Fruiting Vegetables, excluding cucurbits 675 189 56 3 2     0.05 0.4 % 0.13 Bell pepper / TY**
0.11 Bell pepper / TY**
0.067 Green beans / ES
Cucurbits 284 131 59 3       0.1  0 %  
Sprouting Vegetables 336 54 15 1 1     0.05 0.3 % 0.17 Broccoli / ES**
Potatoes, Sweet potatoes,
Topinambur
97 6 4 1       0.05 1 % 0.094 Potatoes / Egypt
Herbal and Fruit Tea 37 36 36 30 24 14 7 0.75 18.9 % 2.2 Moringa Tea / ES**
1.6 Moringa Tea / Tanzania**
1.4 Spearmint Tea
1.3 / 1.1  Peppermint Tea
0.98 Moringa Tea
0.79 Organic Rooibos Tea
Tea 21 11 11 8 8 6 1 0.75 4.8 % 1.3 Oolong / China
Cereal Porridge for babies and small children 7             0.01 0 %  
Baby food, ready-to-eat 25 1           0.01 0 %  

*Measurement uncertainty must be considered

**Verified via the MLs under discussion

 

Products such as Moringa oleifera contained high levels of perchlorate. The dried and ground leaves of the Moringa tree, along with other so-called products marketed as “super food” such as cereal grasses, maca and spiruline, are currently in vogue. Moringa is available on the market in the form of dried moringa leaf powder, as tea, and also as a nutritional supplement. A total of 16 products from these three product categories were analyzed for perchlorate. All of the samples were detected with amounts between 0.075 mg/kg and 2.2 mg/kg. For the products sold as leaf powder, after applying a drying factor of 6, six out of 10 samples exceeded the discussed maximum values for leafy vegetables; among the tea samples, all three were above the recommended maximum value of 0.75 mg/kg for herbal teas. Table 5 presents an overview of all the Moringa samples.

 

Table 5: Amounts of Perchlorate in Moringa Oleifera Products (samples from 2017/18)
Product
Label
Origin
Perchlorate Amount in mg/kg
Amount Based on Fresh Product in mg/kg**
Currently Discussed Maximum Levels (ML)  for Perchlorate in Foods (mg/kg)
Moringa Leaf Powder Organic Unknown 1.6 0.27*** 0.1
Moringa Leaf Powder Organic Thailand 1.5 0.25*** 0.1
Moringa Leaf Powder Organic Unknown 1.2 0.2 0.1
Moringa Leaf Powder Organic Africa 1 0.17 0.1
Moringa Leaf Powder Organic Unknown 0.91 0.15 0.1
Moringa Leaf Powder Organic Unknown 0.55 0.09 0.1
Moringa Leaf Powder Organic Unknown 0.48 0.08 0.1
Moringa Leaf Powder   Unknown 0.41 0.07 0.1
Moringa Leaf Powder Organic Unknown 0.25 0.04 0.1
Moringa Leaf Powder Organic Egypt 0.075 0,01 0.1
Moringa Tea   Spain 2.2***   0.75
Moringa Tea   Tanzania 1.6***   0.75
Moringa Tea   Unknown 0.98   0.75
Moringa Leaf Powder – NS* Organic Unknown 1.7   Not yet discussed 
Moringa Leaf Powder – NS*   Spain 1.2   Not yet discussed
Moringa Leaf Powder – NS*   India 0.99   Not yet discussed

*NS – On the market as a nutritional supplement

**With drying factor of 6

***Verified via the MLs under discussion

 

Do fresh and deep-frozen vegetables differ?

As can be seen in Table 6, there is little difference between fresh and deep-frozen herbs in terms of the number of samples containing perchlorate. For spinach, however, significantly more fresh samples contained perchlorate than frozen, and these contained higher amounts as well. All of the fresh spinach samples contained perchlorate, while just over half of the frozen samples did so. This is also the case for kale, though to a lesser degree. The quantities of perchlorate found in the fresh herbs, spinach and kale were significantly higher than that in the frozen products. In our opinion, these differences for spinach and kale could result from the processes of removing the stems and possibly from the different timing for harvesting the fresh and frozen ware. Frozen spinach is sometimes harvested and sold as „young spinach“, for example.

 

Table 6: Amounts of Perchlorate in Fresh and Deep-Frozen Herbs, Spinach and Kale from 2017/18
Product No. Samples
Samples with Perchlorate (in mg/kg and Percentages)
≥ 0.005 mg/kg
%
≥  0.01 mg/kg
%
≥  0.05 mg/kg
%
≥  0.1 mg/kg
%
≥  0.2 mg/kg

%
Maximum mg/kg
Herbs, fresh 189 148 78 % 106 56 % 28 15 % 9 5 % 2 1 % 0.48
Herbs, deep-frozen 15 12 80 % 6 40 % 2 13 %         0.089
Spinach 52 52 100 % 47 90 % 12 23 % 4 8 %     0.18
Spinach, deep-frozen 11 6 55 % 3 27 %             0.023
Kale 26 24 92 % 23 88 % 5 19 % 1 4 % 1 4 % 2.4
Kale, deep-frozen 16 12 75 % 6 38 % 1 6 % 1 6 % 1 6 % 0.38

 

Is there a difference between conventionally and organically produced foods?

Our analytical results from the last two years did not reveal any significant difference between conventionally and organically grown fresh and deep-frozen vegetables and potatoes in terms of contamination from perchlorate. A total of 2,587 samples of fresh and deep-frozen vegetables and potatoes were analyzed for perchlorate; 268 of these were labelled as organic cultivation.

 

Illustr.1: 	Distribution of Perchlorate Amounts in Conventionally Produced Fresh and Deep-Frozen Vegetables and Potatoes in Samples from 2017/18.

Illustr.1: Distribution of Perchlorate Amounts in Conventionally Produced Fresh and Deep-Frozen Vegetables and Potatoes in Samples from 2017/18.

 

Among conventionally produced vegetables and potatoes, 64 % contained either no perchlorate or less than 0.005 mg/kg. In 18 % of the samples the detected amount was under 0.01 mg/kg, and 33 % of the samples contained less than 0.05 mg/kg. Quantities greater than 0.05 mg/kg were detected in 3.5 % of the samples, and two samples (0.09 %) contained more than 0.5 mg/kg.

 

Illustr. 2: 	Distribution of Perchlorate Amounts in Organically Produced Fresh & Deep-Frozen Vegetables and Potatoes in Samples from 2017 and 2018.

Illustr. 2: Distribution of Perchlorate Amounts in Organically Produced Fresh & Deep-Frozen Vegetables and Potatoes in Samples from 2017 and 2018.

 

Among organically produced vegetables and potatoes, 62 % contained either no perchlorate or less than 0.005 mg/kg. In 21 % of the samples the detected amount was under 0.01 mg/kg and 37 % of the samples contained less than 0.05 mg/kg. Quantities greater than 0.05 mg/kg were detected in 4 (1.5 %) of the samples. None contained perchlorate in amounts over 0.2 mg/kg.
In contrast to the findings for pesticide residues, there was little difference between organic and conventional products in terms of perchlorate quantities detected; at most, there were slightly lower levels in the direction of organic products.

 

Does the country of origin make a difference?

Since the results showed that mainly vegetables can contain perchlorate, and that fruits are seldom affected and, when so, then with low levels, the analyses regarding origins were only conducted for vegetables and potatoes. The origin of deep-frozen products is not known, so these and the few fresh samples without indication of origin were not included in the assessment. The results of these assessments are detailed in Annex 2, and the findings for the more heavily contaminated leafy vegetables are presented in Table 7.

Almost all of the fresh kale samples came from Germany, 91 % of which contained perchlorate; only one sample came from Italy. The spinach samples came from Germany, Italy and Spain; 100 % tested positive. The results for rocket salad looked similar. Herbs were somewhat less contaminated with perchlorate, at 77 %. No major differences between the countries of origin could be determined; the overall percentage of the aforementioned samples containing perchlorate was significantly higher than 50 %. The rate of positive findings for leafy lettuce lay at 41 %. These samples came from a wider variety of countries, which can be due to the wider range of products in this product group. This is also the case for the remaining leafy vegetables as well as for the fruiting vegetables. In general, this shows that the country of origin is not such an important factor for perchlorate contamination as the type of product.

 

Table 7: Amounts of Perchlorate in Selected Fresh Leafy Vegetables, by Country of Origin (>4 samples per country) Complete overview of leafy and fruiting vegetables is in Annex 2
Product Group
No. Samples
Samples Containing Perchlorate
Country of Origin
≥0.005 mg/kg
%
>0.05 mg/kg
>0.2 mg/kg
Median Value mg/kg
Maximum mg/kg
Leafy Lettuce (various) 377 155 41 11 1 0.018 0.27
Germany 277 111 40 6 1 0.016 0.27
Italy 38 21 55 1   0.018 0.08
Spain 34 8 24     0.009 0.016
France 15 5 33     0.012 0.018
Netherlands 7 6 86 3   0.069 0.17
Belgium 5 4 80 1   0.031 0.072
Spinach 51 51 100 12   0.041 0.18
Germany 28 28 100 7   0.038 0.18
Italy 19 19 100 4   0.041 0.14
Spain 4 4 100 1   0.061 0.14
Kale 24 22 92 4 1 0.143 2.4
Germany 23 21 91 4 1 0.148 2.4
Rocket Salad 39 37 95 10   0.037 0.2
Germany 30 29 97 7   0.035 0.2
Italy 8 7 88 2   0.042 0.06
Herbs (various) 164 127 77 22 1 0.031 0.22
Germany 100 76 76 16 1 0.036 0.22
Italy 27 25 93 2   0.019 0.059
India, Israel, Laos, Thailand 18 11 61 1   0.021 0.06
Spain 9 7 78     0.017 0.032
Africa 8 7 88 2   0.043 0.11
Leafy Vegetables excluding leafy lettuce, spinach, kale, rocket salad and herbs 205 52 25 8 2 0.044 0.88
Germany 144 35 24 6 1 0.050 0.88
Netherlands 30 1 3     0.007 0.007
Italy 10 9 90 2 1 0.045 0.27
Turkey 7 3 43     0.020 0.022
Belgium 5 1 20     0.006 0.006
Spain 5 2 40     0.029 0.04

 

 

Infobox

What does the Federal Institute for Risk Assessment (BfR) say?

On 15 February 2018 the Federal Institute for Risk Assessment (BfR) recommended in an updated official statement (No. 006/2018), that efforts be made to reduce the presence of perchlorate in the food chain and thereby the risk to consumers. They also stressed, however, that consumers themselves not alter their eating habits, as the health benefits of fruits and vegetables remains undisputed.[6]

 

Conclusion

In 2013, as part of the food monitoring program in Baden-Württemberg, CVUA Stuttgart began routinely expanding its analyses of pesticide residues in plant-based foods to include perchlorate. Since then, almost 12,000 samples of plant-based foods have been analyzed for the contaminant perchlorate. The overall situation regarding the detected amounts has not changed much. Of the samples tested in 2017 and 2018, 24 % contained perchlorate in concentrations at or above 0.005 mg/kg. Leafy vegetables in particular, including spinach, kale, rocket salad and fresh herbs, were found to contain perchlorate in high concentrations of up to 2.4 mg/kg, while fewer samples of fresh fruit, potatoes, cereals and mushrooms were contaminated, and when so, with low amounts. The establishment of maximum levels for perchlorate as part of the regulation for contaminants has long been discussed. Thus far, no maximum levels have been set, although our analytical results reveal that such a limit would be sensible for protecting consumers; perchlorate was detected in amounts above the limit of determination in about one-fourth of all the analyzed samples. We compared our results from the last two years with the currently discussed maximum limits and determined that very few samples of leafy vegetables contained amounts that would exceed these limits. Among the nutritional supplement products, Moringa leaf powder had high amounts of perchlorate, however. In our opinion, maximum levels for perchlorate in nutritional supplements should also be included in the regulation for contaminants.
In accordance with the ALARA principle, the amounts of contaminants in food should be held as low as technically possible. Whether the maximum levels under discussion provide an incentive for the food industry to reduce the contamination of food from perchlorate remains to be seen. CVUA Stuttgart will continue its analyses. Until maximum levels are established, we will continue to forward our analytical results to food control officers in accordance with the minimization principle stated in Article 2 of Regulation (ECC) No. 315/93, hoping to encourage measures to minimize the quantities of perchlorate in food.  

 

Photo Credits

CVUA Stuttgart, Pesticide laboratory

 

References

[1] EUROPEAN COMMISSION: Statement as regards the presence of perchlorate in food, downloaded on 16 April, 2019

[2] Neu entdeckt: Kontamination von pflanzlichen Lebensmitteln mit Perchlorat

[3] Perchlorat in pflanzlichen Lebensmitteln – ein Update

[4] Richtlinie 2002/63/EG der Kommission vom 11. Juli 2002 zur Festlegung gemeinschaftlicher Probenahmemethoden zur amtlichen Kontrolle von Pestizidrückständen in und auf Erzeugnissen pflanzlichen und tierischen Ursprungs und zur Aufhebung der Richtlinie 79/700/EWG

[5] EFSA: Scientific Opinion on the risks to public health related to the presence of perchlorate in food, in particular fruits and vegetablesdownloaded on 18 April, 2019

[6] BfR: Der Eintrag von Perchlorat in die Nahrungskette sollte reduziert werden downloaded on 16 April, 2019

 

Further Literature

 

Translator:

Catherine Leiblein

 

Appendix

Annex 1: Amounts of Perchlorate in Plant-Based Foods from 2017/2018 and the Recommended Maximum Levels
Product Groups
No. Samples
Samples Containing Perchlorate
Currently Discussed Maximum Levels (ML)  for Perchlorate in Foods
≥ 0.005 mg/kg
>0.01
mg/kg
>0.05
mg/kg
>0.1
mg/kg
>0.2
mg/kg
>0.5
mg/kg
>ML mg/kg
ML in %
Individual
Findings* > ML Recommendation
Berries 546 21 6         0.05  0 %  
Pome Fruit 254  -           0.05 0 %  
Stone Fruit 365 13 6         0.05 0 %  
Citrus Fruit 280 81 39 2       0.05 0.7 % 0.067 Grapefruit / ES
0.056 Pomelo / China
Exotic Fruit 342 34 20 1       0.05 0.3 % 0.059 Pomegranate / Peru
Fruit Juice 39  -                
Dried Fruit*** 43 5 3         ***    
Leafy Vegetables excluding kale, lettuce, spinach, rocket salad and fresh herbs including deep-frozen 224 55 28 8 3 2 1 0.1 1.3 % 0.88 Swiss chard / DE**
0.27 Italian broccoli / IT**
0.16 Celery / DE
Kale, fresh and deep-frozen 42 36 29 6 2 2 1 0.1 0.9 % 2.4 Kale / DE**
0.38 Kale**
Leafy Lettuce 386 160 75 12 4 1   0.1 1.0 % 0.27 Lamb’s Lettuce / DE**
0.17 Cress / NL
0.12 Cress / NL
0.11 Radicchio
Spinach, fresh and deep-frozen 63 58 50 12 4     0.5 0 %  
Rocket Salad 39 37 28 10 1     0.5 0 %  
Herbs, fresh and deep-frozen 204 160 112 30 9 2   0.5 0 %  
Fruiting
Vegetables,
excluding Cucurbit
675 189 56 3 2     0.05 0.4 % 0.13 Bell Pepper / TY**
0.11 Bell Pepper / TY**
0.067 Green beans / ES
Cucurbit 284 131 59 3       0.1 0 %  
Sprouting
Vegetables
336 54 15 1 1     0.05 0.3 % 0.17 Broccoli / ES**
Root Vegetables 237 59 15         0.05 0 %  
Potatoes, Sweet Potatoes,
Topinambur
97 6 4 1       0.05 1 % 0.094 Potatoes / Egypt
Dried Vegetables, Herbs, Spices** 69 58 58 48 30 18 9 ***    
Herbal and
Fruit Tea
37 36 36 30 24 14 7 0.75 18.9 % 2.2 Moringa Tea / ES**
1.6 Moringa Tea / Tanzania**
1.4 Spearmint Tea
1.3 / 1.1 Peppermint Tea
0.98 Moringa Tea
0.79 Organic Rooibos Tea
Tea 21 11 11 8 8 6 1 0.75 4.8 % 1.3 Oolong / China**
Grains (cereals) and Pseudo-Grains 137 6 5         ****    
Legumes, Oil Seeds, Nuts, Soy 168 8 5 1 1     ****    
Mushrooms, fresh and deep-frozen 94 -           ****    
Mushrooms, dried*** 19 6 5 2 1 1   ****    
Cereal Porridge for babies and small children 7  -           0.01    
Baby food, ready-to-eat 25 1           0.01    
Wine and Wine Products*** 73 6 1         ***    
Other 12 8 7 5 3 3 3 ****   1.7 Organic Moringa Leaf Powder (NS)
1.2 Moringa Leaf Powder (NS) / ES
0.99 Moringa Leaf Powder (NS) / India
0.98 Alkalized water (NS) / DE
Total Results 5,118 1,238 673 183 93 49 22      

NS= nutritional supplement

*Measurement uncertainty must be considered

**Verified via the MLs under discussion

***A processing factor must be considered

****No maximum amount recommended

 

Annex 2: Amounts of Perchlorate in Fresh Vegetables and Potatoes, by Country of Origin, from 2017 and 2018 (excluding deep-frozen and „unknown“ countries of origin)
Product Group
No. Samples
Samples Containing Perchlorate
Country of Origin
≥0.005 mg/kg
   %
>0.05 mg/kg
>0.2 mg/kg
Median Value mg/kg
Maximum mg/kg
Leafy Lettuce 377 155 41 11 1 0.018 0.27
Germany 277 111 40 6 1 0.016 0.27
Italy 38 21 55 1   0.018 0.08
Spain 34 8 24     0.009 0.016
France 15 5 33     0.012 0.018
Netherlands 7 6 86 3   0.069 0.17
Belgium 5 4 80 1   0.031 0.072
Greece 1            
Spinach 51 51 100 12   0.041 0.18
Germany 28 28 100 7   0.038 0.18
Italy 19 19 100 4   0.041 0.14
Spain 4 4   1   0.061 0.14
Kale 24 22 92 4 1 0.143 2.4
Germany 23 21 91 4 1 0.148 2.4
Italy 1 1       0.032 0.032
Rocket Salad 39 37 95 10   0.037 0.2
Germany 30 29 97 7   0.035 0.2
Italy 8 7 88 2   0.042 0.06
Morocco 1 1   1   0.075 0.075
Herbs 164 127 77 22 1 0.031 0.22
Germany 100 76 76 16 1 0.036 0.22
Italy 27 25 93 2   0.019 0.059
India, Israel, Laos, Thailand 18 11 61 1   0.021 0.06
Spain 9 7 78     0.017 0.032
Africa 8 7 88 2   0.043 0.11
Portugal 2 1   1   0.097 0.097
Leafy Vegetables excluding leafy lettuce, spinach, kale, rocket salad and herbs 205 52 25 8 2 0.044 0.88
Germany 144 35 24 6 1 0.050 0.88
Netherlands 30 1 3     0.007 0.007
Italy 10 9 90 2 1 0.045 0.27
Turkey 7 3 43     0.020 0.022
Belgium 5 1 20     0.006 0.006
Spain 5 2 40     0.029 0.04
Egypt 2  -          
Bulgaria 1  -          
Poland 1 1       0.005 0.005
Cucurbit 276 126 46 3   0.015 0.077
Germany 96 24 25     0.013 0.044
Spain 92 65 71 2   0.016 0.077
Turkey 24 11 46     0.014 0.044
Netherlands 21 8 38 1   0.019 0.063
South/Central America 16 9 56     0.014 0.037
Italy 13 5 38     0.009 0.012
Greece 4 1       0.007 0.007
Africa 3 2       0.013 0.021
France 3 1       0.007 0.007
Belgium, Bulgaria, Austria 4  -          
Fruiting Vegetables, excluding Cucurbit 592 171 29 3   0.011 0.13
Spain 138 42 30 1   0.011 0.067
Germany 127 20 16     0.010 0.041
Africa 123 60 49     0.010 0.03
Netherlands 66 6 9     0.008 0.011
Thailand, Pakistan, India, Israel 10 4 40     0.010 0.016
Turkey 53 28 53 2   0.018 0.13
Hungaria 27 7 26     0.007 0.009
Belgium 22  -          
Italy 13 2 15     0.006 0.007
Guatemala, Peru 4  -          
France 3  -          
Greece 3 -       0.006 0.006
Poland 2  -          
Cyprus 1          
Sprouting Vegetables 297 50 17 1   0.013 0.17
Germany 155 12 8     0.012 0.046
Spain 55 20 36 1   0.016 0.17
Italy 41 10 24     0.010 0.031
Mexico, Peru 15 3 20     0.010 0.017
France 11          
Netherlands 7  -          
Portugal 5 5 100     0.014 0.021
New Zealand 4          
Greece 3  -          
Egypt 1  -          
Root Vegetables 209 52 25     0.009 0.023
Germany 148 33 22     0.009 0.022
Italy 28 12 43     0.011 0.023
China, Thailand 15 3 20     0.009 0.014
South America 5          
Netherlands 3  -          
France 2  -          
Portugal 2 1       0.018 0.018
Africa 1 1       0.006 0.006
Belgium 1          
Austria 1 1       0.012 0.012
Spain 1          
Hungaria 1  -          
Great Britain 1 1       0.007 0.007
Potatoes, Sweet Potatoes, Topinambur 94 6 6 1   0.036 0.094
Germany 67  -          
Egypt 6 4 67 1   0.051 0.094
France 6 2 33     0.008 0.009
Israel 4  -          
Italy 4          
Portugal 2  -          
Spain 2  -          
Cyprus 2  -          
USA 1  -          
Total Results 2328 849 36 75 5 0.025 2.4

 

Report published on 13.08.2019 10:05:42

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