Paraquat TK, SL

Paraquat TK, SL

PARAQUAT DICHLORIDE TECHNICAL CONCENTRATE (Note 1)

FAO Specification 56.302/TK (October 2021∗)

This specification, which is PART ONE of this publication, is based on an evaluation of data submitted by the manufacturer whose name is listed in the evaluation reports 56.302/2003, 56.302/2020, 56.302/2021). It should be applicable to TK produced by this manufacturer but it is not an endorsement of those products, nor a guarantee that they comply with the specification. The specification may not be appropriate for TK produced by other manufacturers. The evaluation reports (56.302/2003, 56.302/2020, 56.302/2021), as PART TWO, form an integral part of this publication.

1 Description

The material shall consist of paraquat dichloride, together with related manufacturing impurities, in the form of an aqueous solution, free from visible extraneous matter, and must contain an effective emetic (Note 2). The material may also include colorants and olfactory alerting agents.

2 Active ingredient

2.1 Identity tests (56/SL/M/2, CIPAC Handbook G, p.128, 1995)

The active ingredient (paraquat and chloride, Note 3) shall comply with an identity test and, where the identity remains in doubt, shall comply with at least one additional test.

2.2 Paraquat dichloride content (56/SL/M/3, CIPAC Handbook E, p.167, 1993)

The paraquat dichloride content (Note 4) shall be declared (not less than 500 g/l at 20 ± 2ºC, Note 5) and, when determined, the average measured content shall not differ from that declared by more than ± 25 g/l.

3 Relevant impurities

3.1 Free 4,4'-bipyridyl (56/13/M/7.4, CIPAC Handbook 1A, p.1317, 1980)

Maximum: 1.0 g/kg (1000 ppm).

3.2 Total terpyridines (56/SL/M/5, CIPAC Handbook M, p. 141, 2009)

Maximum: 0.001 g/kg (1.0 ppm).

4 Physical properties

4.1 pH range (MT 75.3, CIPAC Handbook J, p. 131, 2000) (Note 1)

pH range: 2.0 to 6.0.

PARAQUAT DICHLORIDE SOLUBLE CONCENTRATE (Notes 1, 2 and 3)

FAO Specification 56.302/SL (October 2021∗)

This specification, which is PART ONE of this publication, is based on an evaluation of data submitted by the manufacturer whose name is listed in the evaluation reports (56.302/2003, 56.302/2020, 56.302/2021). It should be applicable to relevant products of this manufacturer, and those of any other formulators who use only TK from the evaluated source. The specification is not an endorsement of those products, nor a guarantee that they comply with the specification. The specification may not be appropriate for the products of other manufacturers who use TK from other sources. The evaluation reports (556.302/2003, 56.302/2020, 56.302/2021), as PART TWO, form an integral part of this publication.

1 Description

The material shall consist of technical paraquat dichloride, complying with the requirements of FAO Specification 56.302/TK (October 2021), in the form of an aqueous solution (Notes 1 and 2), together with any other necessary formulants, and must contain an effective emetic (Note 3). The material may also include colorants, olfactory alerting agents and thickeners. It shall contain not more than a trace of suspended matter, immiscible solvents and sediment.

2 Active ingredient

2.1 Identity tests (56/SL/M/2, CIPAC Handbook G, p.128, 1995)

The active ingredient (paraquat and chloride components, Note 4) shall comply with an identity test and, where the identity remains in doubt, shall comply with at least one additional test.

2.2 Paraquat dichloride content (56/SL, CIPAC Handbook E, p.167, 1993) (Note 1)

The paraquat dichloride content (Note 5) shall be declared (g/kg and/or g/l at 20 ± 2ºC, Note 6) and, when determined, the average content measured shall not differ from that declared by more than the following tolerances.

Declared content, g/kg or g/l at 20 ± 2ºC      Permitted tolerance

25 up to 100                                                       ± 10% of the declared content

Above 100 up to 250                                        ± 6% of the declared content

Above 250 up to 500                                        ± 5% of the declared content

Note: the upper limit is included in each range.

3 Relevant impurities

3.1 Free 4,4'-bipyridyl (56/13/M/7.4, CIPAC Handbook 1A, p.1317, 1980)

Maximum: 1 g/kg (1000 ppm).

3.2 Total terpyridines (56/SL/M/5, CIPAC Handbook M, p. 141, 2009)

Maximum: 0.001 g/kg (1.0 ppm).

4 Physical properties

4.1 pH range (MT 75.3, CIPAC Handbook J, p. 131, 2000)

pH range: 4.0 to 8.0.

4.2 Dilution stability (MT 41.1, CIPAC Handbook O, p. 174, 2017)

The formulation, after the stability test at 54°C (see 5.2) and following dilution (Note 7) with CIPAC Standard water D and standing at 30 ± 2°C for 24 h, shall give a clear or opalescent solution, free from more than a trace of sediment and visible solid particles. Any visible sediment or particles produced shall pass through a 75 μm test sieve (Note 8).

4.3 Persistent foam (MT 47.3, CIPAC Handbook O, p. 177, 2017) (Note 9)

Maximum: 60 ml after one minute.

5 Storage stability

5.1 Stability at 0°C (MT 39.3, CIPAC Handbook J, p. 126, 2000)

After storage at 0 ± 2ºC for 7 days, the volume of solid and/or liquid which separates shall not be more than 0.3 ml.

5.2 Stability at elevated temperature (MT 46.4, CIPAC Handbook P, p. 232, 2021)

After storage at 54 ± 2ºC for 14 days, the determined average active ingredient content must not be lower than 97%, relative to the determined average content found before storage (Note 10), and the product shall continue to comply with the clause for:

- pH range (4.1).