Regulation (EU) 2019/1009 of the European Parliament and of the CouncilShow full title

4.2. Oil retention test referred to in point 4 under PFC 1(C)(I)(a)(i-ii)(A) in Annex I U.K.

4.2.1. Description U.K.

The oil retention of an EU fertilising product shall be the quantity of oil retained by the EU fertilising product determined under the operating conditions specified and expressed as a % by mass.

The test shall be carried out on a representative sample of the EU fertilising product. Before being tested, the whole mass of the sample shall be thermally cycled two times in accordance with point 4.1.

The method is applicable to both prilled and granular fertilisers which do not contain oil soluble materials.

4.2.2. Principle U.K.

Total immersion of the test sample in gas oil for a specified period, followed by the draining away of surplus oil under specified conditions. Measurement of the increase in mass of the test portion.

4.2.3. Reagents U.K.

Gas oil with the following characteristics:

(a)

viscosity max.: 5 mPas at 40 °C;

(b)

density: 0,8 g/ml to 0,85 g/ml at 20 °C;

(c)

sulphur content: ≤ 1,0 % (m/m);

(d)

ash: ≤ 0,1 % (m/m).

4.2.4. Apparatus U.K.

Ordinary laboratory apparatus, and:

(a)

balance, capable of weighing to the nearest 0,01 g;

(b)

beakers, of capacity 500 ml;

(c)

funnel, of plastic materials, preferably with a cylindrical wall at the upper end, diameter approximately 200 mm;

(d)

test sieve, aperture 0,5 mm, fitting into the funnel;

Note: The size of the funnel and sieve is such as to ensure that only a few granules lie one above another and the oil is able to drain easily.

(e)

filter paper, rapid filtering grade, creped, soft, mass 150 g/m²;

(f)

absorbent tissue (laboratory grade).

4.2.5. Procedure U.K.

4.2.5.1. Two individual determinations are carried out in quick succession on separate portions of the same test sample. U.K.

4.2.5.2. Remove particles smaller than 0,5 mm using the test sieve. Weigh to the nearest 0,01 g approximately 50 g of the sample into the beaker. Add sufficient gas oil to cover the prills or granules completely and stir carefully to ensure that the surfaces of all the prills or granules are fully wetted. Cover the beaker with a watch glass and leave to stand for one hour at 25 (± 2) °C. U.K.

4.2.5.3. Filter the entire contents of the beaker through the funnel containing the test sieve. Allow the portion retained by the sieve to remain there for one hour so that most of the excess oil can drain away. U.K.

4.2.5.4. Lay two sheets of filter paper (about 500 mm x 500 mm) on top of each other on a smooth surface; fold the four edges of both filter papers upwards to a width of about 40 mm to prevent the prills or granules from rolling away. Place two layers of absorbent tissue in the centre of the filter papers. Pour the entire contents of the sieve over the absorbent tissues and spread the prills or granules evenly with a soft, flat brush. After two minutes lift one side of the tissues to transfer the prills or granules to the filter papers beneath and spread them evenly over these with the brush. Lay another sheet of filter paper, similarly with its edges turned upward, on the sample and roll the prills or granules between the filter papers with circular movements while exerting a little pressure. Pause after every eight circular movements to lift the opposite corners of the filter papers and return to the centre the prills or granules that have rolled to the periphery. Keep to the following procedure: make four complete circular movements, first clockwise and then anticlockwise. Then roll the prills or granules back to the centre as described above. This procedure is to be carried out three times (24 circular movements, corners lifted twice). Carefully insert a new sheet of filter paper between the bottom sheet and the one above it and allow the prills or granules to roll onto the new sheet by lifting the edges of the upper sheet. Cover the prills or granules with a new sheet of filter paper and repeat the same procedure as described above. Immediately after rolling, pour the prills or granules into a tared dish and reweigh to the nearest 0,01 g to determine the mass of the quantity of gas oil retained. U.K.

4.2.5.5. Repeating the rolling procedure and reweighing U.K.

If the quantity of gas oil retained in the portion is found to be greater than 2,00 g, place the portion on a fresh set of filter papers and repeat the rolling procedure, lifting the corners in accordance with point 4.2.5.4 (two times eight circular movements, lifting once). Then reweigh the portion.

4.2.5.6. Two oil retention tests per sample are to be carried out. U.K.

4.2.6. Test report U.K.

4.2.6.1. Expression of the results U.K.

4.2.6.1.1. Method of calculation and formula U.K.

The oil retention, from each determination (point 4.2.5.1) expressed as a % by mass of the sieved test portion, is given by the equation:

where:

m₁ is the mass, in grams, of the sieved test portion (point 4.2.5.2),

m₂ is the mass, in grams, of the test portion according to points 4.2.5.4 and 4.2.5.5 respectively as the result of the last weighing.

4.2.6.1.2. Take as the result the arithmetic mean of the two individual determinations. U.K.

4.2.6.2. The test report shall form part of the technical documentation. U.K.