PFC 4: GROWING MEDIUMU.K.
1.A growing medium shall be an EU fertilising product other than soil in situ, the function of which is for plants or mushrooms to grow in.U.K.
For the purpose of this point, plants include algae.
2.Contaminants in a growing medium must not exceed the following limit values:U.K.
(a) cadmium (Cd)
:
1,5 mg/kg dry matter,
(b) hexavalent chromium (Cr VI)
:
2 mg/kg dry matter,
(c) mercury (Hg)
:
1 mg/kg dry matter,
(d) nickel (Ni)
:
50 mg/kg dry matter,
(e) lead (Pb)
:
120 mg/kg dry matter, and
(f) inorganic arsenic (As)
:
40 mg/kg dry matter.
3.The copper (Cu) content in a growing medium must not exceed 200 mg/kg dry matter, and the zinc (Zn) content in a growing medium must not exceed 500 mg/kg dry matter.U.K.
4.Pathogens in a growing medium must not exceed the limits set out in the following table:U.K.
| Micro-organisms to be tested | Sampling plans | Limit | ||
|---|---|---|---|---|
| n | c | m | M | |
| Salmonella spp. | 5 | 0 | 0 | Absence in 25 g or 25 ml |
| Escherichia coli or Enterococcaceae | 5 | 5 | 0 | 1 000 in 1 g or 1 ml |
Where:
n
=
number of samples to be tested,
c
=
number of samples where the number of bacteria expressed in CFU is between m and M,
m
=
threshold value for the number of bacteria expressed in CFU that is considered satisfactory,
M
=
maximum value of the number of bacteria expressed in CFU.