China’s Pesticide Maximum Residue Limit Development Tendencies (GB2763)

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As early as 1990, China started pesticide MRL development. Since then numerous MRLs have been developed by China’s various regulatory authorities in the form of national/industrial standards for agricultural produce or food safety/ standards. This multi-sector development has resulted in overlap and inconsistency in both standards, enforcement and supervision. Since 2010, China began the process of reforming it MRL regulatory framework with the aim of deleting, consolidating and updating the MRLs into a unified food safety standard for pesticide MRLs, known as GB 2763. Up to now the standard has been updated three times and the number of MRLs has increased from 873 in 2012 to 4140 in 2016.

Overview

A total 433 pesticide active ingredients and 286 commodities/ commodity groups are included into GB 2763-2016, covering 70% of the active ingredients approved and most commodities currently consumed in China. Particularly, GB 2763-2016 provides MRLs for all banned/restricted pesticides in all types of commodity.

There are now 1486 MRLs for fruit and 1212 MRLs for vegetables and these two major commodities account for 60% of the total MRLs, reflecting legislator’s prioritization of fresh edible agriculture produce.

Fig.1- Number of MRLs established for Different Commodities

2014 and 2016 Edition Comparison

Compared with the 2014 version, 490 MRLs for 162 active ingredients were added, of which 46 are newly included. Notably, proprietary pesticides and off-patent pesticides occupied a considerable percentage. There is always a substantial increase in experimentation/registration/application in China before or after patent expiry. The authority can thus collect adequate toxicological and residue data to facilitate MRL development.

Fig.2-Common Name and Use Category of Pesticides Newly Included in GB2763-2016 (click on hyperlink to explore the registration status in China)

1

2,4-D-ethylhexyl

herbicide

24

prometryn

herbicide

2

MCPA-isooctyl

herbicide

25

fluthiacet-methyl

herbicide

3

saflufenacil

herbicide

26

metaflumizone

herbicide

4

metamitron

herbicide

27

phenamacril

herbicide

5

metazachlor

herbicide

28

propyzamide

herbicide

6

albendazole

fungicide

29

clothianidin

fungicide

7

pyrethrins

insecticide

30

triphentin acetate

insecticide

8

pyrimorph

fungicide

31

triclopyr

fungicide

9

daminozide

PGR

32

niclosamide ethanolamine

PGR

10

SYP-Z048

fungicide

33

anilofos

fungicide

11

propachlor

fungicide

34

lufenuron

fungicide

12

polyoxin

fungicide

35

terbuthylazine

fungicide

13

metamifop

herbicide

36

prohexadione calcium

herbicide

14

dinotefuran

insecticide

37

penoxsulam

insecticide

15

fluopicolide

fungicide

38

probenazole

fungicide

16

sodium nitrophenolate

PGR

39

enostroburin

PGR

17

sulfentrazone

herbicide

40

uniconazole

herbicide

18

mepiquat chloride

PGR

41

xinjunan

PGR

19

jingangmycin

fungicide

42

bromoxynil octanoate

fungicide

20

trinexapac-ethyl

PGR

43

cyantraniliprole

PGR

21

matrine

insecticide

44

pyrametostrobin

insecticide

22

triasulfuron

herbicide

45

pinoxaden

herbicide

23

pyribenzoxim

herbicide

46

initium

herbicide

These “new” active ingredients accounted for 106 MRLs and covered use in grains, fruit, vegetables, oil crop and sugar respectively. Most new MRLs of “existing” active ingredients are for fruit and vegetable.

Fig.3-Number and Commodity of New MRLs for “New” and “Existing” Active Ingredients

Definition and Commodity Grouping

In addition to the new MRLs, 2016 version made minor adjustment on residue definition and commodity grouping, reflecting China’s continuous effort in MRL development:

Active ingredient

Residue definition in GB 2763-2014

Residue definition in GB 2763-2016

flucarbazone

The sum of flucarbazone and demethylated metabolites

flucarbazone parent compound

Imazapic

Imazapic and its metabolites

Imazapic parent compound

fluopicolide

fluopicolide and its metabolites

Fluopicolide compound

triadimefon and triadimenol

Respectively defined

The sum of triamidefon and tradimenol

  • Temporary MRLs for mefenacet, mepronil and amobam are revised
  • Dried vegetables are separately classified as a major commodity group
  • Green plum (vatica astrotricha) and dried jujube are included into “stone fruits” and “dried fruits” respectively;
  • 11 residue test methods are newly designated, 10 are removed and 28 are revised. All designated methods are launched simultaneously with GB 2763-2016 as the GB 23200 series

Differentiated Management

Since 2000, China has accelerated the substitution of pesticides in its domestic market and plans to remove all highly toxic pesticides except a few irreplaceable one. To prevent illegal use, prohibited/restricted pesticides are managed differently under MRL regulations. MRLs of these pesticides in agricultural produce will be developed as a priority task and group MRLs applicable to multiple commodities will be prioritized over the development of MRLS for single commodities. 18 MRLs of 9 prohibited/restricted pesticides in GB 2763-2014 targeting single commodity have been extrapolated to the whole group.

Both CAC and developed countries have established a specific list of low risk pesticides exempted from MRLs. This successful practice has been used for reference in GB 2763-2016 and 33 pesticides have been included into the exemption list. The natures and toxicological profiles of these substances were comprehensively collected in accordance with “Data Requirement for Pesticide Registration” and reviewed during National Pesticide Registration Committee:

  • Microbial pesticides using low or slightly toxic TC/TK;
  • Botanical pesticides using low or slightly toxic TC/TK;
  • Biochemical pesticides (pheromones, hormones, natural PGRs and enzymes) using low or slightly toxic TC/TK;
  • Low/slightly toxic polysaccharides;
  • Low toxic inorganic pesticides;
  • Mineral Oil and other pesticides using innocuous industrial chemicals

Contemporary Status and Under-improved

The number of MRLs established by CAC is about 5000, 11,000 by the United States, 50,000 by Japan and 100,000 by EU. Moreover, both the United States and Japan have established specific MRLs for susceptible populations such as pregnant woman and children. As China plans to establish 10,000 MRLs by the end of 2020, it is urgent and necessary for China to develop a comprehensive MRL framework covering:

  • National MRL;
  • Temporary MRL;
  • Unified MRLs for pesticide/commodity without an MRL ( Similar to the Positive List System of Japan);
  • Exempted Substance;
  • MRLs for susceptible populations

In GB 2763-2016, MRLs are edited in separate sections which are sorted by the initials of the Chinese common name of each active ingredients. Two indexes can help Chinese or English readers to find the corresponding section/page number for their MRL of interest. The structural sequence is very user-friendly for finding all MRLs for one active ingredient. Finding all applicable MRLs for a certain food commodity is much more difficult. Users have to look up over 400 sections while distinguishing whether the MRL is for a single commodity or for all commodities in the same group. It would a great improvement if both pesticide and commodity expanded search functions were included in the next edition.

GB2763-2016 English Tanslation Free Download

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