Chlorate and Perchlorate in
Fruits and Vegetables
Alexander Lemke
Residues and Contaminants
Department
Outline
• Introduction of CVUA-S / EURL
• Perchlorate and Chlorate
• Chemistry, Usage, Regulations, Toxicology
• Analytical Method
• Perchlorate Results
• Chlorate Results
• Public Health Risks
Stuttgart [ˈʒ̊d̥ua̯ɡ̊ɛʕd̥]
Pop. 600,000
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Capital of Baden-Württemberg federal state
Sister City of St. Louis
Mercedes-Benz
Porsche
‘Cannstatter Wasen’ Beer Festival
CVUA Stuttgart
Chemical and Veterinary
Investigations Office Stuttgart,
Germany
Functions
• Official food control
• Animal health
• Food industry control
• Risk assessment, advisory service
• Research
• Education
Resources
• 243 employees, incl. chemists, microbiologists,
veterinarians
• Annual budget 12 Mio. €, thereof 9 Mio. € for staff
• Area of the building 13,700 m²
European Union Reference Laboratory
for pesticides requiring Single Residue Methods
EURL-SRM
OFL
OFL
OFL NRL
OFL
OFL
OFL NRL
OFL
OFL NRL
OFL
OFL
OFL OFL
NRL OFL
EURL
OFL
OFL
NRL
Main Functions
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•
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•
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Technical assistance to OFLs, NRLs, COM
Method development and validation
Drafting of QAQC guidelines
Organization of EU Proficiency Tests
Networking with NRLs and Official Labs
Workshops, trainings
EURL Datapool www.eurl-pesticides-datapool.eu
NRL National Reference Laboratory
OFL Official Laboratory in an EU Member State
Recent Perchlorate / Chlorate History
2008 – US Agency for Toxic Substances and Disease Registry (ATSDR)
releases public health statement, after widespread presence of
perchlorates in the environment was found
2009 – US CDC finds perchlorate in infant formula
2010 – Chlorate as herbicide banned in the EU
2012 – High levels of perchlorate found in infant formula in France,
assessed as health risk
2012 – CVUA-S begins analyzing food samples for perchlorate
2013 – CVUA-S begins analyzing food samples for chlorate
Usage / Occurrence of Chlorate
Non-agricultural
use
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Agricultural use
• Herbicide (banned in 2010 in EU)
• Defoliant
By-product of
• water treatment with chlorine,
hypochlorite or chlorine dioxide for
• washing of produce;
• post-harvest washing and
sanitation of food (“Hydro-cooling”)
• sanitation of food processing
equipment
Bleaching agent (e.g. paper industry)
metal industry,
leather industry,
pyrotechnics,
cosmetics (disinfectant)
Cl2 + 2 OH3 ClO-
Cl- + ClO- + H2O
ClO3- + 2 Cl-
2 ClO2 + 2 OH-
ClO3- + ClO2-
Usage / Occurrence of Perchlorate
Natural
Natural formation in atmosphere,
accumulation in arid areas,
Chilean nitrate fertilizer
By-product of
Potential degradation of chlorination
agents
Non-agricultural use
solid rocket fuels
(military, aeronautics, pyrotechnics)
O
O
-
Cl
O
O
Toxicity and Regulatory Aspects
Classification in the EU
Chlorate
Perchlorate
Pesticide
Contaminant
Impact on human health reversible inhibition of iodine
uptake in the thyroid;
formation of methemoglobin,
erythrocytes lysis, renal failure
reversible inhibition of iodine
uptake in the thyroid
Acute Reference Dose
(ARfD) (EFSA)
0.036 mg/kg bw
= 36 µg/kg bw
none set
Tolerable Daily Intake
(TDI) (EFSA 2014,15)
3 µg/kg bw and day
0.3 µg/kg bw and day
Regulatory Situation in
the EU
Maximum Residue Level
0.01 mg/kg, but actions are only
taken when ARfD >100%
ALARA-Principle
as low as reasonably achievable
Reference values set for trade
TDI is the daily amount that can be ingested over a life span, without any risk of undesirable health effects
ARfD is defined as the amount of a substance a person can consume, over the period of one day, at one meal.
Analysis of Chlorate and Perchlorate
• Chlorate and Perchlorate are ions ...
… use ion chromatography?
Analysis of Chlorate and Perchlorate
• Chlorate and Perchlorate are ions ...
… use ion chromatography?
• We routinely analyze 1200+ pesticides and
contaminants using LC (and GC) with mass
spectroscopy technology like MS/MS, Qtrap, time-offlight
• New LC-MS/MS based Single Residue Method in 2012:
QuPPe-Method with Hypercarb™-Column
Analysis of Chlorate and Perchlorate
[kjuːb]
http://quppe.eu
Isotopically Labelled Internal Standards
(ILIS) for QuPPe
Electrochemical production of HCl18O3 and HCl18O4
Perchlorate Residues in Food of Plant Origin
Total number of samples
Jan 2013-July 2016: 6814
1377 (20%)
122 (2%)
5315 (78%)
<0.005 mg/kg
≥0.005 ≤0.1 mg/kg
>0.1 mg/kg
Including:
• Fresh Fruit (2498)
• Fresh Vegetables (2966)
• Fruit products (215)
• Vegetable products (244)
• Cereals /-products (146)
• Potatoes (129)
• Mushrooms /-products (201)
Percentage of Samples with Perchlorate Residues
Perchlorate Residues in Food of Plant Origin
16
14.1
14
12
10
13.0
Aug. 2012 - May 2013
June 2013 - Febr. 2014
March 2014 - Feb. 2015
March 2015 - Feb. 2016
11.5
8.3
8
6
4.8
4
2.8
2.4 2.2
1.9
1.1
2
1.3
0.7
0.1
0.2
0.2 0.05
0 0.2 0.1 0.05
0
>0.01 - ≤0.05
>0.05 - ≤0.1
>0.1 - ≤0.5
>1.0
>0.5- ≤1.0
Concentration range (mg/kg)
Perchlorate: Reference Values
ALARA-Principle: as low as reasonably achievable
Categories
Perchlorate Reference Values
(SC PAFF 2015) mg/kg
Samples With High Residues
(03/2015-02/2016)
mg/kg
Fruit and vegetables, with
exception of
0.1
Green beans 0.12
Pumpkin family and leafy
vegetables, with exception of
0.2
Cucumber 0.48
Melon 0.41
Celery and spinach from
greenhouses
0.5
Spinach 0.47
Herbs, rucola, head lettuce, lettuce
from greenhouses
1.0
Rosemary 4.8
Dill 0.3; Parsley 0.26
Arugula 0.22; Head lettuce 0.18
Source: EUROPEAN COMMISSION DIRECTORATE-GENERAL FOR HEALTH AND FOOD SAFETY: Statement as regards the presence of
perchlorate in food, endorsed by the Standing Committee on Plants, Animals, Food and Feed on 10 March 2015, updated on 23 June 2015;
http://ec.europa.eu/food/safety/docs/cs_contaminants_catalogue_perchlorate_statement_food_update_en.pdf
Percentage of Samples with Perchlorate Residues
Perchlorate Residues in Food of Plant Origin
16
Aug. 2012 - May 2013
June 2013 - Febr. 2014
March 2014 - Feb. 2015
March 2015 - Feb. 2016
14.1
14
12
10
13.0
11.5
<1% of samples
above general reference value
for fruits and vegetables
8.3
8
6
4.8
4
2.8
2.4 2.2
1.9
1.1
2
1.3
0.7
0.1
0.2
0.2 0.05
0 0.2 0.1 0.05
0
>0.01 - ≤0.05
>0.05 - ≤0.1
>0.1 - ≤0.5
>1.0
>0.5- ≤1.0
Concentration range (mg/kg)
How does Perchlorate end up in food?
• Anthropogenic sources ?
• Superficial vs. systemic contamination?
• By-product of chlorinated washing / process water?
• By-product of chlorinated irrigation water?
• Natural nitrate fertilizers with perchlorate?
Perchlorate – Distribution Within Melons
Perchlorate (mg/kg)
Peel
Sample
Fruit Flesh
0.067
0.020
Honeydew
Galia melon
0.056
0.026
0.019
0.021
0.046
0.044
Galia melon
Galia melon
Cantaloupe
Cantaloupe
0.023
0.028
0.033
0.065
Perchlorate and Chlorate in Fertilizers
Melamine
1
Osmosol
2
Naersalz GT 15_5_30
3
Entec perfect 15_5_20
4
Haifa NK 13_46
5
PerlkaKalkstickstoff
1,7
6
Blaukorn
0,39
7
Nitrophoska
8
KaliumKrista
9
Calcinit
10
ASS Bor
11
Krista K NK
12
Triabon Langz.
13
Fery NPK_Mg
0,055
14
Patentkali
0,016
15
Agriplant 15_5_30
16
NPK_Duenger
17
Novatek
18
Perlka
19
Yara Calcinit
0,091
7,3
5,9
TriazolDiethanolamin Triethanolamin Anilin
8,4
0,051
29
0,034
0,003
0,11
0,057
0,041
41
0,027
0,031
78
0,041
0,32
0,033
0,035
14
0,031
0,13
0,014
Triazol Acetic Triazole
acid
lactic acid
0,067
Cyanuric
acid
0,068
0,086
Chlorate
Perchlorate
0,51
21
37
27
14
15
20
8,1
11
0,30
0,076
0,039
0,04
0,033
2,4
2,7
0,049
0,080
0,056
0,019
0,088
0,25
0,025
0,2
0,88
41
0,061
0,024
0,024
0,032
0,087
0,019
0,041
0,019
0,03
2,1
Perchlorate and Chlorate - Correlation ?
1
Samples with Perchlorate > 0.20 mg/kg
and Chlorate > 0.30 mg/kg
0,5
0
2
1,5
1
0,5
0
Chlorate
Perchlorate
Chlorate Residues in Food of Plant Origin
Total number of samples
April 2014-July 2016: 4718
439 (9%)
95 (2%)
4184 (89%)
Default Maximum Residue Level
0.01 mg/kg
<0.01 mg/kg
≥0.01 ≤0.1 mg/kg
>0.1 mg/kg
How does Chlorate end up in food?
• Chlorinated irrigation water
• Recycled process water for washing / desinfection
• Washing with chlorinated water after harvest
• Application of contaminated fertilizers
• Illegal use of chlorate as herbicide
Percentage of samples
Chlorate Residues in Food of Plant Origin
8
7.5%
April 2014 - March 2015
April 2015 - March 2016
6.7%
7
6
5
4
3
2.1% 2.0%
2
1.8% 1.5%
0.5%
1
0
>0.01-≤0.05
>0.05-≤ 0.1
>0.1 -≤0.5
concentration range (mg/kg)
>0.5
0.3%
Chlorate Residues in Fruit and (Frozen) Vegetables
77.8
Percentage of samples
80
76.9
75.5
65.7
70
60
54.3
50
40
30
20
10
18.0
18.3
15.9
18.3
14.7
2.4
3.3
1.5
1.7
3.0
Summer
2014
Winter
2014/15
Summer
2015
Winter
2015/16
2Q 2016
0
Fruits % ≥0.01 mg/kg
Vegetables % ≥0.01 mg/kg
Frozen Vegetables % ≥0.01 mg/kg
Chlorate in Fresh and Frozen Vegetables
No. of samples with/without chlorate residues
Brussels
CauliSpinach Chive sprouts Broccoli flower
0
10
fresh
20
11
frozen
5
8
44
2
15
34
3
5
fresh
frozen
2
38
fresh
frozen
50
12
fresh
frozen
40
without residues (≤0.01 mg/kg)
with residues (> 0.01 mg/kg)
fresh
frozen
30
42
12
7
10
60
Chlorate Residues in Carrots
31
27
35
30
25
20
15
10
5
0
16
5
5
0
Carrots
fresh
Carrots
prepared
Carrots
frozen
No of samples with chlorate ≥0.01mg/kg
No of samples
Chlorate Residues in Prepared Carrots
from different manufacturers
mg/kg
0.6
0,6
0.54
0,5
0.5
0.4
0,4
0.28
0,3
0.3
0.24
0.2
0,2
0,1
0.1
0.14
0.097
0.049 0.071
0.036 0.043
<0.01
0
A
B
Origin Netherlands Origin USA
C
Origin USA
D
Origin unknown
Chlorate Residues in Asparagus
No. of samples
39
40
35
30
25
20
15
5
9
7
10
1
7
4
3
0
0
0
0
Peru
Italy
Germany
Greece
Residues ≤ 0.01 mg/kg
Residues > 0.01 mg/kg
Spain
Chlorate – Acute Exposure from Single Samples
Commodity
Origin
Chive frozen
Unknown
3.8
2.5 %
Coriander leaf
Thailand
1.7
0.6 %
Egg plant
Netherlands
1.2
83 %
Chili pepper
Uganda
0.96
168 %
Asparagus green Peru
0.91
12 %
Head lettuce
0.72
127 %
April 2015 – March 2016
Germany
Chlorate % ARfD exhaustion
(mg/kg) for most vulnerable
age group
Chlorate: Acute Dietary Exposure Estimate
95th percentile
µg/kg bw /day
Age Class
Infants
Toddlers
Other Children
Adolescents
Adults
Elderly
Very elderly
Mean exp.
µg/kg bw /day
main contributor: drinking water !
7.6
7.2
5.2
3.0
2.9
2.9
2.7
17.3
15.3
11.0
7.2
6.9
6.0
5.3
ARfD: 36 µg/kg bw
Source: EFSA CONTAM Panel (EFSA Panel on Contaminants in the Food Chain), 2015. Scientific Opinion on risks for public health related to the presence of chlorate in food.
EFSA Journal 2015;13(6):4135, 103 pp. doi:10.2903/j.efsa.2015.4135
Chlorate: Chronic Dietary Exposure Estimate
95th percentile
µg/kg bw /day
Age Class
Infants
Toddlers
Other Children
Adolescents
Adults
Elderly
Very elderly
Mean exp.
µg/kg bw /day
main contributor: drinking water !
2.6
3.2
2.4
1.4
1.3
1.1
1.1
4.3
5.2
3.9
2.3
2.2
1.9
1.8
TDI: 3 µg/kg bw /day
Most vulnerable subpopulation:
Younger age groups with iodine deficiency
Source: EFSA CONTAM Panel (EFSA Panel on Contaminants in the Food Chain), 2015. Scientific Opinion on risks for public health related to the presence of chlorate in food.
EFSA Journal 2015;13(6):4135, 103 pp. doi:10.2903/j.efsa.2015.4135
Conclusion (1)
• Food safety control for perchlorate contamination is working
• Low public health risk for average consumer at current
average chlorate exposure levels
Conclusion (2)
• Current regulatory situation for chlorate is unsatisfactory,
both for food companys and food safety officials
• MRL of 0.01 mg/kg or future ALARA-reference value for
chlorate might still be a good idea because:
• cumulative and synergistic effects,
• formation of carcinogenic halogenated DBP
Conclusion (3)
• More research and data needed!
• Chlorate occurrence in food
• Human dietary exposure to chlorate
• Human health impact of chlorate
• Impact of food processing on chlorate residues
Conclusion (3)
• Compliance with general food safety regulations requires
desinfection of some kind on most production stages
• Efforts to reduce chlorate residues in food must not have an
negative impact on microbiological food safety.
Thank you for your
attention.
Visit www.cvuas.de for more details on
chlorate and perchlorate in fruit and
vegetables!