In Netherlands, Roam Technology has obtained a unique authorization for the continuous dosing of the well-known Huwa-San technology in irrigation systems. As a result, Dutch growers now have access to a biocide that can be continuously dosed in-line to maintain water quality and keep biofilm under control.
The approval follows a period of increased attention to the use of hydrogen peroxide products in Dutch horticulture. Hydrogen peroxide is widely used in greenhouse horticulture for the control of bacteria and biofilm in irrigation systems. While the active substance is approved under European biocides legislation, individual products require national authorization in the Netherlands through the Ctgb, with compliance enforced by the Dutch Food and Consumer Product Safety Authority (NVWA).
During the past year, the NVWA carried out inspections into the use of biocides at agricultural businesses, identifying cases where products were not being applied according to their authorized instructions. This considered the widespread use of continuous or inline dosing, whereas most existing authorizations only covered shock treatments. The findings raised considerable concern across the greenhouse horticulture sector and highlighted the growing importance of water hygiene and clear regulations.
At the same time, Roam Technology worked extensively behind the scenes on a structural and compliant solution for the use of hydrogen peroxide in irrigation systems, including throughout crop production. The company developed an approach that enables growers to maintain reliable water hygiene both during crop changeovers and throughout the entire growing cycle.
A compliant approach to biofilm and water hygiene in irrigation systems with Huwa-San
Huwa-San TR-50 Plus is a new stabilized hydrogen peroxide product based on the well-known Huwa-San technology. It was specifically developed for continuous dosing in irrigation systems used in protected cultivation, designed to control biofilm and maintain consistent water hygiene throughout the growing season.
The product can be applied throughout the entire irrigation system, including pipes, sprinklers, drippers, silos, tanks, and associated equipment.
Following an extensive evaluation process, Huwa-San TR-50 Plus now received a positive assessment from the Dutch Board for the Authorization of Plant Protection Products and Biocides (Ctgb) during its meeting on 27 May 2026. As a result, the continuous use of Huwa-San TR-50 Plus against biofilm throughout the entire irrigation system has been officially authorized for the Dutch market under authorization number 16500 N.
"The approval of Huwa-San TR-50 Plus is a milestone that we fully stand behind. The Ctgb handled the Huwa-San TR-50 Plus dossier with great integrity and on a scientific basis throughout the process, which gives us confidence as a science-driven company," says Caroline Clijsters, CTO of Roam Technology.
"This authorization sends an important message to growers: with this product, irrigation systems can be kept clean during cultivation, and the correct application of TR-50 Plus is therefore considered safe use. Our experts are ready to support growers in implementing it."
"With Huwa-San TR-50 Plus, growers finally have a compliant and future-oriented solution to keep biofilm formation consistently under control while maintaining optimal water quality in their irrigation systems."
Ctgb decision
The Ctgb decision of 27 May 2026 has been published. Below is a direct translation of the official authorization (16500 N) for Huwa-San TR-50 Plus.
A. Legal Conditions of Use
The product is authorized exclusively for use as:
- the preservation of irrigation water for protected, soilless greenhouse cultivation against bacteria (excluding mycobacteria and bacterial spores) and biofilm, in order to prevent clogging of irrigation systems (including pipes, sprinklers, drippers, silos, tanks, and associated equipment);
- the preservation of cooling water in closed systems against bacteria (including Legionella, but excluding mycobacteria and bacterial spores) and biofilm.
The instructions for use described under Section B must be followed.
Protective gloves, protective clothing, and eye/face protection must be worn when handling undiluted Huwa-San TR-50 Plus.
Application in irrigation systems is only permitted in greenhouses that discharge into the sanitary sewer system. Direct discharge of irrigation water into surface water is not permitted.
The product is intended for professional use only.
B. Instructions for Use
Thoroughly clean the system (equipment/installation/piping/circulation system) before treatment. If a cleaning agent is used, rinse with drinking water afterward. Remove any excess water.
Irrigation Water Treatment
Shock Treatment (Curative) for Biofilm
Dosage: 50 ppm hydrogen peroxide
Contact time: 24 hours
Fill the open or closed installation with a 50 ppm solution of the active substance (1 ml of product per 10 liters of water) and allow it to remain in contact for at least 24 hours.
During treatment, vent the distribution or circulation system as necessary.
If the system is heavily contaminated with slime or biofilm, flush the system after treatment to remove the loosened slime and biofilm residues.
Continuous Treatment (Preventive)
For bacteria: 40 ppm hydrogen peroxide
For biofilm: 50 ppm hydrogen peroxide
Fill the installation with either:
a 50 ppm solution (for biofilm control), or
a 40 ppm solution (for bacterial control),
and allow the product to circulate continuously throughout the system.
Vent the system when used in a closed distribution or recirculation system.