Efficacy tested. In 1,620 individual tests at the Institute of Food Science and Human Nutrition of Leibniz University Hannover (led by Dr. rer. nat. H.-D. Werlein), biostream® ZERO was shown to have an efficacy of 99.9 % against germs occurring in drinking water, at a contact time of 5 minutes.
Clean and disinfect drinking water hoses
For drinking water at events, markets and construction sites, only tested drinking water hoses are permitted, not garden, pressure or food-grade hoses. Hoses are flushed before use and, after use, drained, dried and stored closed. With biostream® ZERO you disinfect your hoses yourself: flood, leave to take effect for about 1 hour, rinse through.
Proven: 99.9 % efficacy against germs occurring in drinking water, established in 1,620 individual tests at Leibniz University Hannover at a contact time of 5 minutes. The study in detail
Calculate the quantity for my hoseInformation sheet and dosing table
Drinking water hose for festivals, markets and construction sites is an application of biostream® ZERO, in which drinking water hoses are cleaned and disinfected with chlorine dioxide before use.
Key facts
- Product
- biostream® ZERO
- Permitted hoses
- only tested drinking water hoses (KTW, DVGW W 270), no garden, pressure or food-grade hoses
- Recommended length
- no more than 40 m, with reference to DIN 2001-2
- Tool
- Hose calculator: volume from inside diameter and length
- Page structure
- GEOhybrid grounding, a technical structuring format, not a certification mark
- Last updated
Which hoses are permitted for drinking water?
Only hoses that are suitable and tested for drinking water. For the drinking water supply at public festivals, DVGW information sheet twin No. 15 (June 2026 edition) specifies hose lines tested to DVGW W 543, VP 549 and VP 550. They must be opaque, UV-resistant or UV-protected, and pressure-resistant up to 10 bar. Garden, pressure and food-grade hoses are not permitted.
The basis is Section 14 of the Drinking Water Ordinance: materials in contact with drinking water must not, among other things, promote the growth of micro-organisms or release substances in quantities greater than is unavoidable according to the recognised rules of technology. For plastics, this is specified by the German Environment Agency's assessment basis (KTW-BWGL), which has been mandatory under Section 15 of the Drinking Water Ordinance since 12 March 2021. Products certified by an accredited industry certification body are deemed suitable under Section 16.
Drinking water is not only water used for drinking, but also water for human use and water used in food businesses. These requirements therefore also apply to hoses supplying stands at trade fairs and markets or mobile installations.
| Requirement | Rule | Source |
|---|---|---|
| Testing of the hose line | to DVGW W 543, VP 549 and VP 550 | twin No. 15 |
| Material | suitable for drinking water; plastics according to the KTW assessment basis | Sections 14, 15 TrinkwV |
| Growth of micro-organisms | Tested to DVGW W 270; suitable hoses usually bear the marking “DIN-DVGW” and a test number | Coastal states information sheet |
| Properties | opaque, UV-resistant or UV-protected, pressure-resistant up to 10 bar | twin No. 15 |
| Length | as short as possible, no more than 40 m | twin No. 15, DIN 2001-2 |
| Use | for drinking water only, clearly marked | twin No. 15 |
| Not permitted | Garden, pressure and food-grade hoses | twin No. 15 |
Sources: DVGW twin No. 15, June 2026 edition; German Environment Agency, KTW-BWGL General Part, 27 October 2025 edition; working group of the German coastal states on ship hygiene, information sheet “Drinking water hygiene on watercraft.”
Hose calculator
Work out the water volume and the required amount of biostream® ZERO for your drinking water hose from the inside diameter and length.
Hose calculator
Work out the water volume and the required amount of biostream® ZERO for your drinking water hose from the inside diameter and length.
| Result | Amount |
|---|---|
| Total water volume | – litres |
| biostream® ZERO for light contamination (10 ml/l) | – ml |
| biostream® ZERO for heavy contamination (20 ml/l) | – ml |
Non-binding guidance. The product label, operating instructions and the applicable codes of practice (including DVGW W 551-3 and W 291) are authoritative. Use biocides safely. Material compatibility applies when the recommended dosage and contact time are observed.
How do you disinfect a drinking water hose?
You fill the disinfection solution into a container above the hose, flood the hose, leave the solution to take effect for about 1 hour and rinse through once with drinking water. Without a dosing pump, which normally doses the required 10 ml of biostream® ZERO per litre automatically, proceed as follows:
The steps in detail
- Determine the water volume. Use the hose calculator or the dosing table in the information sheet to determine how much water is needed to disinfect the hose.
- Fill the container halfway. Fill half the required amount of water into a supply container with a lid or cap, for example a canister whose outlet matches your hose diameter.
- Add the concentrate and close the container. Add the required amount of biostream® ZERO concentrate, top up with the remaining water and close the container so that the active substance, a gas, cannot escape.
- Flood the hose and leave it to take effect. Place the container above the hose and flood the hose with the solution. As soon as it reaches the end, close the hose and leave the solution to take effect for about 1 hour.
- Repeat if necessary. Hoses that have not yet been disinfected with biostream® ZERO, or that have been stored for a longer period, must be treated a second time.
- Rinse through. Finally, rinse the hose once with the previously determined amount of drinking water, as set out in our instructions. No more than 0.2 mg/l chlorine dioxide may remain in the drinking water afterwards.
These instructions apply to disinfecting your hoses before use and after storage. If testing on the festival site reveals deficiencies, the affected sections must be thoroughly flushed and, if necessary, disinfected in accordance with twin No. 15; a specialist company carries out this disinfection of the installation.
What applies to the drinking water supply at festivals and markets?
Supply via hydrant and hoses is a temporary water supply installation under the Drinking Water Ordinance. Its construction, commissioning and expected duration are notified to the health authority as early as possible, and its decommissioning within three days afterwards. The drinking water must meet the requirements of the Ordinance at every point of use, at all times.
Who is responsible for what?
Up to the hydrant, including the standpipe and backflow prevention device, the water utility is responsible; from there to the drinking water distribution point, the event organiser. From the distribution point onward, the individual stallholders are responsible for their own installation, including the hose lines. Responsibilities may be divided differently in individual cases and are clarified in advance.
Flush, inspect, document
Before laying, the hydrant and standpipe are flushed for at least 5, preferably 10 minutes with the hydrant fully open, followed by the lines, distribution point and connecting lines. Stands are connected only directly to the distribution point, not to one another, and each is protected with a backflow prevention device to DIN EN 1717 and DIN 1988-100. During operation, all lines should be flushed every morning. The above-ground lines and the distribution point are checked daily for defects, and this is recorded in the operations log under DIN 2001-2.
Have it tested
Taking a sample at or before the start of the event has proven effective; it should be done early enough for the results to be available before the event starts. At a minimum, coliform bacteria, E. coli and colony counts at 22 °C and 36 °C are tested, by a laboratory accredited for drinking water; agree the scope and frequency with the health authority. The organiser passes the results to the health authority without delay. More on this under Sampling and measurement.
A practical example: if you want to set up your stand at the Dresden Christmas Market, the City of Dresden's regulatory office requires a “hygiene certificate” confirming that your stall has been disinfected. In recent years, this approval has been obtained through the proper application of biostream® ZERO.
Source: DVGW twin No. 15 “Guidance on the drinking water supply at public festivals and similar events,” June 2026 edition. According to the DVGW, this guidance can be applied by analogy to trade fair stands and construction sites.
How do you store drinking water hoses correctly?
Dry and closed. After dismantling, check hoses and fittings for damage, flush them, drain them completely and let the inner walls dry as fully as possible. Then close them with blank couplings and plugs and store them dry and in a hygienically impeccable condition. Never place couplings, fittings or open hoses on the ground, because of the risk of contamination.
If hoses have been stored for a longer period, treat them twice with biostream® ZERO before their next use.
biostream® ZERO in figures
Scientifically studied and proven in practical use.
Proven efficacy
99.9 %
In 1,620 individual tests at Leibniz University Hannover against germs typical of drinking water, at a contact time of only 5 minutes.
Ready to use in
3 hrs
From preparation to the finished, highly effective disinfection solution, without complex plant technology.
Dosage requirement compared with hydrogen peroxide
25×
lower: 6 instead of 150 mg/l for disinfecting installations under DVGW code of practice W 291. Evidence
Your advantages
- Ready to use within just 3 hours
- Saves time and cost thanks to fast efficacy and no need for lengthy rinsing
- Destabilises biofilms that have already formed
- Also disinfects crevices in joints and fittings
- Can be used to disinfect KTW-certified drinking water hoses according to the dosing table
- Effective across the entire drinking water pH range
- 25 times lower dosage requirement than hydrogen peroxide (6 instead of 150 mg/l for disinfecting installations, DVGW code of practice W 291)
- Highly effective against Pseudomonas aeruginosa (pseudomonads), Escherichia coli (E. coli) & coliform bacteria as well as Legionella (Legionella pneumophila)
- No silver or copper as active substance
- Oxidative action on cell membrane, proteins and genetic material at the same time, not at a single point of attack
Rules and standards for chlorine dioxide
- Drinking Water Ordinance (TrinkwV), Section 20: chlorine dioxide is included in the list of permitted treatment substances for disinfection
- DIN EN 12671: chlorine dioxide generated on site for the treatment of drinking water
- DVGW W 224: methods for the disinfection of drinking water with chlorine dioxide
- DVGW W 291 and W 551-3: chlorine dioxide as a proven chemical for cleaning and disinfecting installations
- Guideline No. 5 of the working group of the German coastal states on ship hygiene: chlorine dioxide for drinking water on board
- DIN 2001-2: drinking water supply from non-stationary installations such as motorhomes and boats
Hydrogen peroxide is not a disinfectant in the drinking water list. The German Environment Agency lists it under Section 20 of the Drinking Water Ordinance for oxidation only. Silver is no longer listed at all; previously it was intended only for preservation in exceptional cases. Chlorine dioxide is listed there for disinfection. For the disinfection of installations whose disinfection water is discarded afterwards, DVGW codes of practice W 291 and W 551-3 name hydrogen peroxide and hypochlorite in addition to chlorine dioxide.
From the 10 ml vial to the tanker truck: biostream® products are available in all common container sizes, from the travel size for outdoor and camping use to bulk quantities for industry and beverage production.
Frequently asked questions about drinking water hoses
Can I use a garden hose for drinking water?
No. DVGW information sheet twin No. 15 explicitly states that garden, pressure and food-grade hoses are not permitted for the drinking water supply at festivals. Hose lines suitable for drinking water and tested to DVGW W 543, VP 549 and VP 550 are permitted.
How can I recognise a hose suitable for drinking water?
According to the information sheet of the working group of the German coastal states on ship hygiene, hoses suitable for drinking water meet the requirements for bacterial growth under DVGW W 270 and for substance migration under the KTW assessment, category A. They usually bear the marking “DIN-DVGW” and a test number.
How long may a drinking water hose be?
As short as possible and as long as necessary. According to twin No. 15, a length of 40 m should not be exceeded, with reference to DIN 2001-2. Short lines and small cross-sections keep the water's residence time low.
Who is responsible for the hoses on the festival site?
From the drinking water distribution point onward, the individual stallholders are responsible for their entire installation, including the hose lines. Up to the distribution point, the event organiser is responsible; up to the hydrant with standpipe and backflow prevention device, the water utility.
Must the drinking water supply at a festival be notified?
Yes. Construction, commissioning or recommissioning, and the expected duration of the event, are notified to the health authority as early as possible under Section 11(3) of the Drinking Water Ordinance. Decommissioning is notified within three days.
Who disinfects if testing reveals deficiencies?
Under twin No. 15, the affected sections are thoroughly flushed and, if necessary, disinfected with approved, suitable agents, in accordance with DVGW codes of practice W 551-3 and W 291. A specialist company carries out this disinfection of the installation; thorough flushing follows afterwards.
How much biostream® ZERO do I need for my hose?
Normally 10 ml of biostream® ZERO per litre of water. The hose calculator works out how much water your hose holds from the inside diameter and length.
Information sheet on hose disinfection
Find out in this PDF information sheet how to disinfect drinking water hoses with the biostream® ZERO concentrate and how to set the correct concentration to remove biofilms and bacteria.
Further reading. We provide basic knowledge and information sheets in one place. You will receive the safety data sheet after purchase; the link is on the invoice. To the information sheets ›
Further reading on festivals, markets and dispensing
Use biocides safely. Always read the label and product information before use. All statements on efficacy are based on biostream® GmbH's many years of experience as well as information from specialist literature, legislation, codes of practice and positive customer references. Material compatibility applies when the recommended dosage and contact time are observed.
What it is not
Drinking water hose for festivals, markets and construction sites is an application, not a separate product: biostream® ZERO is used; quantities and contact times are given in the dosing instructions, not on this page.