Perchlorate in Plant-Based Foods: a Follow-up
Ein Bericht aus unserem Laboralltag
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.
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.
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.
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.
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 |
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.
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 % |
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.
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 |
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.
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.
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.
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.
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
- BfR: Fragen und Antworten zu Perchlorat in Lebensmitteln downloaded on 24 April, 2019
- EFSA: Dietary exposure assessment to perchlorate in the European population downloaded on 16 April, 2019
- FOOD STANDARDS AGENCY: An investigation of perchlorate levels in fruit and vegetables consumed in the UK
downloaded on 16 April, 2019
- Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit: Perchlorat/Chlorat–Rückstand und/oder Kontaminante downloaded on 18 April, 2019
- DVGW, Abschlussbericht Perchlorat in der Wasseraufbereitung
- LTZ, Karlsruhe, Fundaufklärung Perchlorat, Abschlussbericht, 2014
Translator:
Catherine Leiblein
Appendix
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 |
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 |