More new growing media with RHP quality mark available thanks to adjusted standard

8 april 2022

After approval by the Technical Committee, changes were made to module 330 (General product requirements Horticulture) of the RHP product certification scheme. There is only a dosage restriction for the same raw material from different origins in one substrate. And this only applies to raw materials for which a plant response test is necessary. This means that considerably more new growing media with the RHP quality mark can be supplied.

Due to the introduction of the plant response test, RHP has gained a lot of experience with non-peat raw materials since last year. It has been found that there is much less need to take into account the addition of any growth inhibitions. Only in the case of the same raw material from different origins for which a plant response test is required. By adapting the formula from module 330, there are much less dosage restrictions for RHP-certified raw materials in substrates. With a view to the raw materials transition, this is an important change. This is because considerably more new growing media with the RHP quality mark can be supplied. This is important for among others recipe developers and account managers within RHP-certified companies.

Adjusted formula

Previously, different raw materials with a dosage restriction could only be used proportionally in a substrate, calculated according to a certain formula. That formula has now been adjusted. If the same raw material from different origins – for which a plant response test is required – is used in one substrate mixture, these raw materials may be mixed in proportionally. For example, this may apply to bark from supplier A and bark from supplier B. The dosage restriction is determined by the plant response test. The formula below applies here, in which the same raw material but from different origins must be included in volume percentages. The result must be less than or equal to 1.

Module 330 at My RHP

The complete adjusted module 330 is available at My RHP in the RHP product certification scheme. Certified companies need to have implemented all the current requirements from the RHP product certification scheme in their business operations and quality management system before May 1st.

Haven’t you got a personal account for My RHP yet? As an employee of an RHP certified company you can easily create one for yourself via my.rhp.nl.

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