Chlorpyrifos TC, EC

Chlorpyrifos TC, EC

CHLORPYRIFOS TECHNICAL MATERIAL

FAO Specification 221 / TC (February 2020)

This specification, which is PART ONE of this publication, is based on an evaluation of data

submitted by the manufacturers whose names are listed in the evaluation reports

(221/2002, 221/2004, 221/2006, 221/2008, 221/2014 & 221/2019). It should be applicable

to TC produced by these manufacturers but it is not an endorsement of those products, nor

a guarantee that they comply with the specifications. The specification may not be

appropriate for TC produced by other manufacturers. The evaluation reports (221/2002,

221/2004, 221/2006, 221/2008, 221/2014 & 221/2019), as PART TWO, form an integral

part of this publication.

1 Description

The material shall consist of chlorpyrifos together with related manufacturing

impurities and, below its melting point (Note 1), shall be a white to tan coloured

crystalline solid, free from visible extraneous matter and added modifying agents.

2 Active ingredient

2.1 Identity tests (221.b/TC/M/2, CIPAC Handbook 1C, p. 2028, 1985) (Note 2)

The active ingredient shall comply with an identity test and, where the identity

remains in doubt, shall comply with at least one additional test.

2.2 Chlorpyrifos content (221.b/TC/M/3, CIPAC Handbook 1C, p.2028, 1985)

The chlorpyrifos content shall be declared (not less than 970 g/kg) and, when

determined, the average measured content shall not be lower than the declared

minimum content.

3 Relevant impurities

3.1 Sulfotep (O,O,O’,O’-tetraethyl dithiopyrophosphate, CAS No. 3689-24-5) (Note 3)

Maximum: 3 g/kg

3.2 Acetone insolubles (MT 27, CIPAC Handbook F, p. 88, 1995)

Maximum retained on a 45 μm test sieve: 5 g/kg

4 Physical properties

4.1 Acidity (MT 191, CIPAC Handbook L, p. 143, 2006)

Maximum acidity: 1 g/kg calculated as H2SO4

CHLORPYRIFOS EMULSIFIABLE CONCENTRATE

FAO Specification 221 / EC (February 2020)

This specification, which is PART ONE of this publication, is based on an evaluation of

data submitted by the manufacturers whose names are listed in the evaluation reports

(221/2002, 221/2004, 221/2006, 221/2008). It should be applicable to relevant products

of these manufacturers, and those of any other formulators who use only TC 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 TC from other sources. The

evaluation reports (221/2002, 221/2004, 221/2006, 221/2008), as PART TWO, form an

integral part of this publication.

1 Description

The material shall consist of technical chlorpyrifos (complying with the requirements

of WHO specification 221/TC (February 2020) dissolved in suitable solvents together

with any necessary formulants. It shall be in the form of a stable and homogeneous

pale yellow to amber coloured liquid, free from visible suspended matter and

sediment, to be applied as an emulsion after dilution in water.

2 Active ingredient

2.1 Identity tests (221.b/EC/M/2, CIPAC Handbook 1C, p. 2031, 1985) (Note 1)

The active ingredient shall comply with an identity test and, where the identity

remains in doubt, shall comply with at least one additional test.

2.2 Chlorpyrifos content (221.b/EC/M/3, CIPAC Handbook 1C, p. 2031, 1985)

The chlorpyrifos content shall be declared (g/kg or g/l at 20 ± 2°C, Note 2) and, when

determined, the average measured content shall not differ from that declared by

more than the following amounts:

Declared content in g/kg or g/l at 20 ± 2°C         Tolerance

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 in each range the upper limit is included

3 Relevant impurities

3.1 Sulfotep (O,O,O’,O’-tetraethyl dithiopyrophosphate, CAS No. 3689-24-5) (Note 3)

Maximum: 3 g/kg (0.3%) of the chlorpyrifos content found under clause 2.2.

4 Physical properties

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

The pH of a 1 % aqueous dispersion shall be 4.5 to 6.5.

4.2 Emulsion stability and re-emulsification (MT 36.3, CIPAC Handbook K,

p. 137, 2003) (Note 4)

The formulation, when diluted at 30 ± 2°C with CIPAC Standard Waters A and D,

shall comply with the following:

Time after dilution         Limits of stability

0 h                                    Initial emulsification complete

0.5 h                                 'Cream', maximum: 2ml

2.0 h                                 'Cream', maximum: 2ml

                                          'Oil', maximum: trace

24 h                                  Re-emulsification complete

24.5 h                               'Cream', maximum: 2ml

                                          'Oil', maximum: trace

Note: tests after 24 h are required only where the results at 2 h are in doubt.

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

Maximum: 20 ml after 1 minute.

5 Storage stability

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

After storage at 0 ± 2°C for 7 days, the volume of solid or liquid which separates shall

not be more than 0.3 ml.

5.2 Stability at elevated temperature (MT 46.4) (Note 5)

After storage at 54 ± 2°C for 14 days, the determined average active content shall

not be lower than 95%, relative to the determined average content found under 2.2

before storage (Note 6), and the formulation shall continue to comply with the

clauses for:

- pH range (4.1);

- emulsion stability/re-emulsification (4.2).