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

• Capital of Baden-Württemberg federal state

• Sister City of St. Louis

• Mercedes-Benz

• Porsche

• ‘Cannstatter Wasen’ Beer Festival

Stuttgart [ˈʒ̊d̥ua̯ɡ̊ɛʕd̥] Pop. 600,000

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

EURL

NRL

NRL

NRL

NRL

NRL

OFL OFL

OFL OFL

OFL

OFL

OFL OFL

OFL

OFL

OFL

OFL

OFL

OFL OFL

European Union Reference Laboratory

for pesticides requiring Single Residue Methods

EURL-SRM

NRL National Reference Laboratory

OFL Official Laboratory in an EU Member State

Main Functions • 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

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

• Bleaching agent (e.g. paper industry)

• metal industry,

• leather industry,

• pyrotechnics,

• cosmetics (disinfectant)

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

3 ClO- ClO3

- + 2 Cl

-

Cl2 + 2 OH- Cl

- + ClO

- + H2O

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)

ClO

O

OO

-

Toxicity and Regulatory Aspects Chlorate Perchlorate

Classification in the EU 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-of-

flight

• New LC-MS/MS based Single Residue Method in 2012:

QuPPe-Method with Hypercarb™-Column

Analysis of Chlorate and Perchlorate

[kjuːb]

http://quppe.eu

Electrochemical production of HCl18O3 and HCl18O4

Isotopically Labelled Internal Standards

(ILIS) for QuPPe

Perchlorate Residues in Food of Plant Origin

Including:

• Fresh Fruit (2498)

• Fresh Vegetables (2966)

• Fruit products (215)

• Vegetable products (244)

• Cereals /-products (146)

• Potatoes (129)

• Mushrooms /-products (201) 5315 (78%)

1377 (20%)

122 (2%)

<0.005 mg/kg≥0.005 ≤0.1 mg/kg >0.1 mg/kg

Total number of samples

Jan 2013-July 2016: 6814

Perchlorate Residues in Food of Plant Origin

0

2

4

6

8

10

12

14

16

>0.01 - ≤0.05 >0.05 - ≤0.1 >0.1 - ≤0.5 >0.5- ≤1.0 >1.0

14.1

4.8

2.4

0.1 0

13.0

2.8 2.2

0.2 0.2

11.5

1.9 1.3

0.2 0.1

8.3

1.1 0.7

0.05 0.05

Aug. 2012 - May 2013

June 2013 - Febr. 2014

March 2014 - Feb. 2015

March 2015 - Feb. 2016

Pe

rcen

tage o

f S

am

ple

s w

ith

Pe

rchlo

rate

Resid

ue

s

Concentration range (mg/kg)

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

Perchlorate: Reference Values

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

Perchlorate Residues in Food of Plant Origin

0

2

4

6

8

10

12

14

16

>0.01 - ≤0.05 >0.05 - ≤0.1 >0.1 - ≤0.5 >0.5- ≤1.0 >1.0

14.1

4.8

2.4

0.1 0

13.0

2.8 2.2

0.2 0.2

11.5

1.9 1.3

0.2 0.1

8.3

1.1 0.7

0.05 0.05

Aug. 2012 - May 2013

June 2013 - Febr. 2014

March 2014 - Feb. 2015

March 2015 - Feb. 2016

Pe

rcen

tage o

f S

am

ple

s w

ith

Pe

rchlo

rate

Resid

ue

s

Concentration range (mg/kg)

<1% of samples

above general reference value

for fruits and vegetables

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

Peel Sample Fruit Flesh

0.067 Honeydew 0.056

0.020 Galia melon 0.026

0.019 Galia melon 0.023

0.021 Galia melon 0.028

0.046 Cantaloupe 0.033

0.044 Cantaloupe 0.065

Perchlorate (mg/kg)

Perchlorate and Chlorate in Fertilizers Melamine Diethanolamin Triethanolamin

Triazol-

Anilin

Triazol Acetic

acid

Triazole

lactic acid

Cyanuric

acid Chlorate Perchlorate

1 Osmosol 8,4 0,051 0,068 0,51

2 Naersalz GT 15_5_30 29 0,067 0,086 21 37

3 Entec perfect 15_5_20 0,091 0,034 0,30

4 Haifa NK 13_46 0,003 0,076

5 PerlkaKalkstickstoff 1,7 0,11 0,039 0,04 2,4

6 Blaukorn 0,39 0,057 0,033 2,7

7 Nitrophoska 0,041 0,049

8 KaliumKrista 41 0,080 27 14

9 Calcinit 0,027 0,056

10 ASS Bor 7,3 0,031 0,019 0,088

11 Krista K NK 78 0,25 15 20

12 Triabon Langz. 0,041 0,025 0,2 0,88 41

13 Fery NPK_Mg 0,055 0,32 0,061

14 Patentkali 0,016 0,033 0,024

15 Agriplant 15_5_30 0,035 0,024

16 NPK_Duenger 14 0,032 0,087 8,1 11

17 Novatek 0,031 0,019

18 Perlka 5,9 0,13 0,041 0,03 2,1

19 Yara Calcinit 0,014 0,019

Perchlorate and Chlorate - Correlation ?

0

0,5

1

1,5

2

0

0,5

1

Chlorate Perchlorate

Samples with Perchlorate > 0.20 mg/kg

and Chlorate > 0.30 mg/kg

4184 (89%)

439 (9%)

95 (2%)

<0.01 mg/kg≥0.01 ≤0.1 mg/kg >0.1 mg/kg

Chlorate Residues in Food of Plant Origin

Total number of samples

April 2014-July 2016: 4718

Default Maximum Residue Level

0.01 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

Chlorate Residues in Food of Plant Origin

0

1

2

3

4

5

6

7

8

>0.01-≤0.05 >0.05-≤ 0.1 >0.1 -≤0.5 >0.5

7.5%

2.1% 1.8%

0.5%

6.7%

2.0% 1.5%

0.3%

April 2014 - March 2015

April 2015 - March 2016

concentration range (mg/kg)

Pe

rce

nta

ge

of sa

mp

les

Chlorate Residues in Fruit and (Frozen) Vegetables P

erc

en

tage

of sa

mp

les

0

10

20

30

40

50

60

70

80

Summer2014

Winter2014/15

Summer2015

Winter2015/16

2Q 2016

2.4 3.3 1.5 1.7 3.0

18.0 18.3 15.9

18.3 14.7

77.8 75.5

54.3

65.7

76.9

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

11

5

44

38

2

34

3

42

12

8

2

12

15

5

10

7

0 10 20 30 40 50 60

fresh

frozen

fresh

frozen

fresh

frozen

fresh

frozen

fresh

frozen

Cauli-

flow

er

Bro

cco

liB

russels

spro

uts

Ch

ive

Sp

inach

without residues (≤0.01 mg/kg)

with residues (> 0.01 mg/kg)

Chlorate Residues in Carrots

0

5

10

15

20

25

30

35

Carrotsfresh

Carrotsprepared

Carrotsfrozen

0

16

5

31 27

5

No of samples with chlorate ≥0.01mg/kg

No of samples

Chlorate Residues in Prepared Carrots from different manufacturers

0

0,1

0,2

0,3

0,4

0,5

0,6

<0.01 0.036

0.049

0.043

0.071

0.28

0.24

0.14

0.54

0.097

mg/kg

A

Origin Netherlands B

Origin USA C

Origin USA

D

Origin unknown

0.5

0.4

0.3

0.2

0.1

0.6

Chlorate Residues in Asparagus

0

5

10

15

20

25

30

35

40

Peru Italy Germany Greece Spain

1 3

39

9

4 7

0 0 0

7

No

. o

f sa

mple

s

Residues ≤ 0.01 mg/kg Residues > 0.01 mg/kg

Commodity Origin Chlorate

(mg/kg)

% ARfD exhaustion

for most vulnerable

age group

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 Germany 0.72 127 %

April 2015 – March 2016

Chlorate – Acute Exposure from Single Samples

Chlorate: Acute Dietary Exposure Estimate

Age Class Me

an e

xp.

µg/

kg b

w /

day

95

th p

erc

en

tile

µg/

kg b

w /

day

Infants 7.6 17.3

Toddlers 7.2 15.3

Other Children 5.2 11.0

Adolescents 3.0 7.2

Adults 2.9 6.9

Elderly 2.9 6.0

Very elderly 2.7 5.3

ARfD: 36 µg/kg bw

main contributor: drinking water !

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

main contributor: drinking water !

Age Class Me

an e

xp.

µg/

kg b

w /

day

95

th p

erc

en

tile

µg/

kg b

w /

day

Infants 2.6 4.3

Toddlers 3.2 5.2

Other Children 2.4 3.9

Adolescents 1.4 2.3

Adults 1.3 2.2

Elderly 1.1 1.9

Very elderly 1.1 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!