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

Report from a day in the lab

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.

 

 

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.

 

 

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 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)

 

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

 

 

Report published on 04.05.2020 10:53:12