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Chlorpyrifos Is „OUT“: This Insecticide May No Longer Be Used In the EU

Ein Bericht aus unserem Laboralltag

Ellen Scherbaum, Nadine Korte

 

It’s news that no news agent or NGO has overlooked: „EU Forbids Insect Killer Chlorpyrifos“ or „Chlorpyrifos: EU-Commission Bans Controversial Insecticide“.

According to an official opinion of the European Food Safety Authority (EFSA) in August 2019, the pesticide chlorpyrifos does not fulfill the criteria legally required for an extention of its authorized use in the European Union. Analyses show: this substance has an affect on human health.

 

Photo: Fruits.

 

As early as May 2012 American researchers published findings in the Proceedings of the National Academy of Sciences (PNAS) that chlorpyrifos had a detrimental effect on brain development of the unborn [3,4]. But as so often happens, the results were initially doubted, the number of cases so small, the test controversial. Moreover, this substance has been on the market for 60 years and used in a variety of applications.

 

Chlorpyrifos – A Factsheet

The insecticide and acaricide chlorpyrifos has been used to combat sucking and biting insects in agriculture, against storage pests, against ectoparasites in animal husbandry and in the household.


Chlorpyrifos belongs to the large group of phosphonic acid esters whose insecticide effect is based on an inhibition of the cholinesterase. Its triumphal march began after World War II. In contrast to the organochlorine compounds, which are persistent in the environment, organophosphates degrade very quickly. Although their acute toxicity is high ((E605 (parathion) won some dubious prominence in suicide cases because the inhibition of the cholinesterase especially leads to the cramping of the intestinal tract and can result in death due respiratory paralysis), their chronic toxicity is assessed to be rather low.


In 2014 the European Food Safety Association (EFSA) undertook a new toxicological evaluation of chlorpyrifos and adjusted the acceptable daily intake (ADI, chronic toxicity) as well as the acute reference dosage (ARfD, acute toxicity) downward (see Info Box) [5]. Other adjustments followed: in 2016 and 2018 several maximum residue levels were also lowered.

 

Info Box

Chlorpyrifos

  • Implemented in the mid 1960’s
  • Used extensively many years as, e.g. insecticide
  • Non-systemic contact, poisonous effect on stomach & respiratory system
  • EFSA’s 2014 Acute Reference Dose reduced to 0.005 mg/kg bodyweight
  • EFSA’s 2014 Acceptable Daily Intake reduced to 0.001 mg/kg bodyweight and day
  • Authorization for use in the EU ended 16 Feb. 2020
  • Transitional period for depletion of existing substance expired 18 April 2020

 

Acute Reference Dose (ARfD)

For the evaluation of pesticides that have a high, acute toxicity and that can cause health damage after just a single or short-term intake, the Acceptable Daily Intake (ADI) value is only appropriate to a limited extent. Since the ADI is derived from long-term studies, it is possibly inadequate as a measure of acute risk from residues in food. Therefore, in addition to the ADI value, a further exposure limit has been established, the so-called acute reference dose (ARfD). The World Health Organization defines the ARfD as the amount of a substance one can consume over the period of one day or in one meal without resulting in any discernible health risk. Other than for the ADI, the ARfD value is not determined for every pesticide, but only for such substances that, when taken in sufficient quantities, could cause damage to one’s health even after just one exposure.

 

Chlorpyrifos residues – what have we analyzed and what has changed since 2010?

Since 2010 we have analyzed about 20,900 samples of plant-based food from conventional production for residues of chlorpyrifos. Ten percent of the samples were detected with this substance and 51 (0.2 %) exceeded the then maximum valid level.


Citrus fruits were especially found to contain chlorpyrifos residues; 55 % of the analyzed samples contained detectable amounts, followed by spices, tea and nutritional supplements such as moringa.  


Table 1 shows an overview of the results.

 

Table 1: Residues of chlorpyrifos in conventionally produced, plant-based foods (CVUAS, 2010–2019)
Food Group Sub-Group
No. of Samples
% of Samples Positive for Chlorpyrifos
Ave. Value mg/kg
Max mg/kg
Min mg/kg
Alcohol-free drinks  
225
11 (4.9 %)
0.003
0.007
0.001
Baked goods  
31
-
 
 
 
Beer & hops/barley  
27
1 (3.7 %)
0.022
 
 
Fats & Oils  
145
25 (17.2 %)
0.019
0.079
0.001
Vegetables Leafy Veg.
3615
182 (5 %)
0.12
15.9
0.001
Exotic Veg.
4
-
 
 
 
Fruiting Veg.
3525
149 (4.2 %)
0.025
0.84
0.001
Mixed Veg.
10
-
 
 
 
Sprouting Veg.
1115
52 (4.7 %)
0.005
0.025
0.001
Root Veg.
695
20 (2.9 %)
0.011
0.052
0.001
Vegetable products  
526
57 (10.8 %)
0.13
4.4
0.001
Cereals  
229
9 (3.9 %)
0.007
0.018
0.002
Cereal products  
95
2 (2.1 %)
0.004
0.005
0.002
Spices  
159
72 ( 45.3 % )
0.026
0.21
0.001
Legumes, oil seeds, nuts, soy  
273
21 (7.7 %)
0.041
0.19
0.008
Potatoes & starchy plant-parts  
406
7 (1.7 %)
0.043
0.14
0.001
Fruit Berries
2795
216 (7.7 %)
0.016
0.31
0.001
Exotic Fruit
1680
200 (11.9 %)
0.012
0.15
0.001
Seed Fruit
997
135 (13.5 %)
0.042
1.1
0.001
Stone Fruit
1537
168 (10.9 %)
0.008
0.13
0.001
Citrus Fruit
1195
659 (55.1 %)
0.041
0.62
0.001
Fruit products  
465
90 (19.4 %)
0.018
0.28
0.001
Mushrooms  
500
3 (0.6 %)
0.002
0.003
0.001
Mushroom products  
127
32 (25.2 %)
0.024
0.2
0.001
Baby food  
61
1 (1.6 %)
0.002
 
 
Tea  
100
38 (38 %)
0.028
0.23
0.005
Wine & wine products  
251
-
 
 
 
Seasoning sauces  
2*
2
0.008
0.013
0.002
Additives  
2*
1
0.10
 
 
Nutritional supplements (Moringa)  
15
9 (60 %)
0.045
0.33
0.001
Other foods  
54
2 (3.7 %)
0.004
0.007
0.001
Cotton clothing  
50
-
 
 
 
Consumer food contact products  
14
4 (28.6 %)
0.026
0.049
0.002
TOTAL Results  
20926
2168 (10.4 %)
0.037
15.9
0.001

*No percentage is given for sample sizes under 5

 

Calculations for country of origin show significant differences. While every second sample from China had chlorpyrifos residues, it has never been used in New Zealand (see Table 2). Only the countries with more than 50 analyzed samples are listed.

 

Table 2: Residues of chlorpyrifos in conventionally produced plant-based foods, by country of origin (CVUAS, 2010–2019)
Country
No. of Samples
Positive Samples
% of Positive Samples
China
258
135
52.3
India 143 43 30.1
Vietnam 62 18 29.0
Turkey 906 234 25.8
Thailand 124 27 21.8
Argentina 102 22 21.6
Peru 242 51 21.1
Spain 2751 553 20.1
Italy 1566 290 18.5
Columbia 100 17 17.0
Chile 356 56 15.7
Greece 132 20 15.2
USA 68 9 13.2
Mexico 61 8 13.1
Egypt 161 21 13.0
Israel 219 27 12.3
Kenya 107 12 11.2
Brazil 340 35 10.3
South Africa 620 63 10.2
Serbia 55 5 9.1
Ghana 68 5 7.4
Costa Rica 234 15 6.4
France 326 14 4.3
Poland 197 8 4.1
Morocco 409 15 3.7
Hungary 64 2 3.1
Belgium 199 6 3.0
Germany 7537 80 1.1
Netherlands 596 3 0.5
New Zealand 78 0 0.0

 

The rate of MRL exceedances is quite low, at 0.2 %. Table 3 shows the type of matrices and their countries of origin, which are quite diverse. The most conspicuous findings were those from Turkey, with 17 samples exceeding the maximum level (bell peppers, pomegranates, lentils, chili peppers, quinces, pickled wine leaves and lemons).

 

Table 3: Exceedances of the MRL for chlorpyrifos, itemized by type of food and country of origin (CVUAS, 2010–2019)
Food Matrix Country of Origin
Samples > MRL
Pineapple Costa Rica
1
Apricot France
1
Basil Cambodia
1
Laos
1
Thailand
1
Unknown
1
Pear Spain
1
Green bean Italy
1
Cambodia
1
Spain
1
Thailand
1
Dill Italy
1
Peanut China
3
Unknown
1
Bell pepper Turkey
2
Moringa powder Unknown
1
Oregano Unknown
1
Pomegranate Turkey
5
Cucumber, frozen Vietnam
1
Currant, frozen Poland
1
Potato Germany
2
Coriander Thailand
1
Unknown
1
Leek Italy
1
Lentil Turkey
2
Mango Africa
1
Ivory Coast
1
Nectarine Spain
1
Chili pepper Turkey
1
Peach South Africa
1
Quince Turkey
2
Pickled grape leaves Egypt
1
Bulgaria
1
Greece
1
Turkey
4
Unknown
1
Lemon Spain
1
Turkey
1
TOTAL Results  
51

 

Citrus Fruits

The highest rate of positive samples is among citrus fruits. We’ve analyzed approximately the same number of citrus samples over the past 10 years, so we can make a good comparison (see also Table 4 and Diagram 1).

 

Assessments must consider that chlorpyrifos is not a systemic substance. That means it isn’t taken up into the plant’s interior from the soil via its vessel system. A majority of the residues are on the peel, which normally isn’t eaten [6].

 

Table 4: Residues of chlorpyrifos in conventionally produced citrus fruit (CVUAS, 2010–2019)
Year
No. of Samples
Positive Samples
Ave. Value mg/kg
Max mg/kg
Samples > Max. Level
2010
129
84 (65.1 %)
0.055
0.62
-
2011
147
90 (61.2 %)
0.034
0.24
-
2012
135
93 (68.9 %)
0.060
0.30
-
2013
104
73 (70.2 %)
0.044
0.30
-
2014
96
68 (70.8 %)
0.046
0.23
-
2015
117
77 (65.8 %)
0.037
0.29
-
2016
106
58 (54.7 %)
0.033
0.30
-
2017
141
68 (48.2 %)
0.021
0.27
1
2018
109
31 (28.4 %)
0.026
0.22
1
2019
111
17 (15.3 %)
0.039
0.28
-

 

 

Diagram 1: Percent of positive samples in conventionally produced citrus fruits (CVUAS, 2010-2019).

Diagram 1: Percent of positive samples in conventionally produced citrus fruits (CVUAS, 2010–2019)

 

Diagram 1 presents the percentage of samples with quantifiable chlorpyrifos residues (gray columns). The samples that exceeded the „new“ residue MRL of 0.01 mg/kg (blue columns) were also calculated. A noticeable reductive trend can be seen from 2016; the new toxicological assessments from EFSA were carried out in 2014.

 

The situation for citrus fruits from Spain is even more notable. It is quite evident here that the producers reacted quickly and that, in the meantime, chlorpyrifos has been practically eradicated.

 

Diagram 2: Spanish citrus fruits with chlorpyrifos residues, in % (CVUAS, 2010-2019).

Diagram 2: Spanish citrus fruits with chlorpyrifos residues, in % (CVUAS, 2010–2019)

 

Of course, the interesting question for the consumer is which insecticide will now take the place of chlorpyrifos in Spanish citrus production (see Table 5).

 

Table 5: The three most commonly used insecticides in conventionally produced citrus fruits from Spain (CVUAS, 2015–2019)
Year
Insecticide Substances
Frequency of Detection in Spanish Citrus Fruits (%)
2015
Chlorpyrifos
70.8
Pyriproxyfen
58.3
Chlorpyrifos-methyl
31.3
2016
Chlorpyrifos
58.8
Pyriproxyfen
54.9
Chlorpyrifos-methyl
17.6
2017
Pyriproxyfen
72.3
Chlorpyrifos
47.7
Chlorpyrifos-methyl
40.0
2018
Pyriproxyfen
64.5
Chlorpyrifos-methyl
37.1
Chlorpyrifos
29.0
2019
Pyriproxyfen
56.7
Chlorpyrifos-methyl
48.3
Spirotetramat, sum
30.0

 

As Table 5 shows, pyriproxyfen, chlorpyrifos-methyl and spirotetramat were frequently applied in 2019. EU authorization for chlorpyrifos-methyl was also not extended, however. This means that the Spanish citrus fruit producers will have to once again make adjustments.

 

Samples from organic production

We have analyzed about 4,000 samples of plant-based foods from organic production for residues of chlorpyrifos since 2010. Three percent of these contained this substance, albeit mostly in only trace amounts smaller than 0.01 mg/kg (see Table 6). Traces of substances can also occur in the end product as a result of drifting, cross-contamination during the harvest, packaging or marketing. Only 10 samples contained residues of 0.01 mg/kg or above (Table 7). All samples were in compliance with the valid MRLs.

 

Table 6: Chlorpyrifos in organically produced, plant-based foods (CVUAS, 2010–2019)
Food Group Sub-Group
No. of Samples
Chlorpyrifos positives
Ave. Value mg/kg
Max mg/kg
Min mg/kg
Alcohol-free drinks  
78
2 (2.6 %)
0.004
0.006
0.001
Baked goods  
15
-
 
 
 
Fats, Oils  
96
5 (5.2 %)
0.006
0.011
0.003
Vegetables Leafy Veg.
475
12 (2.5 %)
0.003
0.009
0.001
Fruiting Veg.
556
2 (0.4 %)
0.003
0.003
0.002
Sprouting Veg.
126
2 (1.6 %)
0.003
0.005
0.001
Root Veg.
186
2 (1.1 %)
0.004
0.007
0.001
Vegetable products  
160
10 (6.3 %)
0.012
0.025
0.001
Cereals  
142
2 (1.4 %)
0.002
0.002
0.002
Cereal products  
100
2 (2 %)
0.006
0.009
0.002
Spices  
36
-
 
 
 
Legumes, Oil seeds, Nuts, Soy  
244
5 (2 %)
0.007
0.009
0.006
Potatoes & Starchy plant-parts  
79
-
 
 
 
Nutritional supplements  
7
2 (28.6 %)
0.010
0.011
0.009
Fruit         Berries
223
2 (0.9 %)
0.001
0.001
0.001
Exotic Fruit
189
9 (4.8 %)
0.004
0.01
0.001
Seed Fruit
197
5 (2.5 %)
0.001
0.003
0.001
Stone Fruit
93
8 (8.6 %)
0.003
0.008
0.001
Citrus Fruit
252
24 (9.5 %)
0.003
0.008
0.001
Fruit products  
292
33 (11.3 %)
0.004
0.008
0.001
Mushrooms & Mushroom products  
86
-
 
 
 
Baby food  
128
-
 
 
 
Tea  
49
4 (8.2 %)
0.020
0.043
0.006
Pasta products  
21
-
 
 
 
Wine & Wine products  
151
-
 
 
 
Seasoning sauces  
11
2 (18.2 %)
0.003
0.003
0.003
Other  
42
-
 
 
 
TOTAL Results  
4034
133 (3.3 %)
0.005
0.043
0.001

 

Table 7 lists the samples from organic production that have contained chlorpyrifos in amounts of 0.01 mg/kg or above in the past 10 years, since 2010. These have mainly involved moringa, barley grass and camomile tea, products that undergo a drying process, which tends to concentrate the residues. This must be factored into the assessment, which resulted in all of these samples adhering to the legal guidelines.

 

Table 7: Chlorpyrifos amounts in organically produced, plant-based foods containing or exceeding 0.01mg/kg (CVUAS, 2010–2019)
Year Sample Type Country of Origin
Quantity mg/kg
2015 Banana Mexico
0.01
2017 Moringa Thailand
0.01
2016 Moringa Thailand
0.01
2012 Olive oil Unknown
0.011
2017 Moringa Unknown
0.011
2019 Moringa Unknown
0.011
2017 Moringa Unknown
0.012
2017 Moringa Unknown
0.021
2012 Camomile tea Egypt
0.023
2016 Barley grass Bulgaria
0.025
2016 Moringa India
0.025
2018 Camomile tea Unknown
0.043

 

Summary

Approximately 10 % of the conventionally produced samples analyzed over the past 10 years have contained chlorpyrifos residues, especially those coming from China, India, Vietnam and Turkey. Now the substance is no longer permitted for use in the EU and the maximum amounts will be set at the limit of quantification of 0.01 mg/kg.


Enormous efforts and the most stringent of requirements ensure that authorization is only given for pesticides that present no risk to our health. However, this is only possible within the realm of our current scientific knowledge. It is therefore meaningful and important that pesticides be regularly re-assessed. The list of substances that have lost this authorization over the years is long. Examples include old chloro-organic substances such as DDT and lindane; endocrine effective substances such as vinclozolin and procymidon; some phosphonice acid esters such as E605; and neonicotinoids such as clothianidin and pyrethroids, etc.


For consumers that are especially concerned about their health, organic produce provides an alternative. Although 3 % of our samples tested positive for chlorpyrifos, these were only in trace amounts, probably the result of drifting or cross-contamination.

 

Photo credit

CVUA Stuttgart, Andrea Karst, pesticide laboratory.

 

References

[1] Stuttgarter Zeitung: EU verbietet Insektenkiller Chlorpyrifos, retrieved on 13 Jan. 2020

[2] Zeit: EU-Kommission verbietet umstrittenes Insektizid, retrieved on 4 Feb. 2020

[3] Virginia Rauh et al, PNAS May 15, 2012 109 (20) 7871–7876

[4] Spiegel: Pestizid schädigt Gehirne Ungeborener, retrieved on 13 Jan. 2020

[5] European Food Safety Authority EFSA : Chlorpyrifos: Bewertung ergibt Auswirkungen auf die menschliche Gesundheit, retrieved on 13 Jan. 2020

[6] Food Safety Magazine: Distribution of Chlorpyrifos Residues in Citrus Fruits, retrieved on 17 Jan. 2020

 

Translated by: Catherine Leiblein

 

Artikel erstmals erschienen am 04.05.2020 10:53:12

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