Questions and answers

We’ve collected the most frequently asked questions about sterile filtration* and their answers for you here:

*This content is not valid for the U.S. market.
For an overview of our products for the U.S. market,
please visit our U.S. website.

  • Sterile filters by i3 Membrane have a lifespan of 50 days. Within this period, they can be used safely and without limitations. Bacterial retention, the bacteriostatic action of the filter surface and an adequate flow rate are ensured throughout the filters' usage life.

  • In addition to the capacity of the filter, the efficacy of the bacteriostatic filter surface, which protects against a retrograde contamination, is a factor limiting the length of time for which sterile filters can be used. Extensive testing and clinical investigations have shown that the bacteriostatic efficacy of the high performance plastic materials begins to drop after more than 50 days of use. This is why i3 Membrane's sterile filters should not be used for longer than 50 days.

  • When i3 Membrane's sterile filters are used for longer than the specified 50 days, we do not guarantee the function and efficacy of our products.

  • The filters have a validated shelf or storage life of 5 years. The expiry date is marked on the product packaging and labeled with an hour-glass symbol.

  • i3's filters for medical sterile filtration are single-use products. They can be discarded with the household trash after they have been used. When removing the filter, follow the instruction for use.

  • Yes, i3's Point-of-Use sterile filters intended as infection prevention are CE-marked Class I medical devices. What's more, as a manufacturer of medical devices, we have a quality management system that is certified in accordance with DIN EN ISO 13485 and thus complies with the standard's demanding requirements relating to the safety and reliability of its products and services, as well as the minimization of the risks of our products.

  • The i3 ONE and i3 TWO connect Point-of-Use filters are attached to the water faucet or the shower hose using a quick-release fastening. i3 TWO direct has a standard screw thread that allows it to be attached directly to the shower hose. Please see the following instructions for use for the exact installation and removal procedures: i3 ONE instruction for use, i3 TWO connect instruction for use, i3 TWO direct instruction for use.

  • The high performance flat membranes used in i3's sterile filters are designed so that the flow rate is adequate even when the water quality is low. However, if very large amounts of particulate matter (e.g. rust, sand) are present in the drinking water, the flow rate may be reduced, and the membrane's lifespan may be shortened as a result.

  • If you are ordering from us for the first time, we need a written order (e.g. by e-mail to as well as the name of your company. Please also include your billing address, delivery address and the name and telephone number of the person to be contacted in case of any questions.

    As a returning customer, you can order by e-mail or phone. In this case, all we need for verification is your customer number.

    The i3 Membrane filters will be dispatched the next day and delivered within 2 to 3 workdays. Express delivery can be arranged for an additional fee upon request.

  • Yes, the surface of i3 Membrane's sterile filters can be disinfected by wiping. This means you can include the filters in your hospital's daily cleaning and disinfection routine. A current list of permitted disinfectants for i3 Membrane products is available here.

  • i3 Membrane's sterile filters consist of a microfiltration membrane with a pore size of 0.2 µm, which show to have a validated microbial retention rate equivalent to LRV > 7 log per cm2 (Brev. dim.) according to ASTM F838.

  • When it comes to medicine, biocompatibility means that materials or assemblies do not have a negative impact on living tissue when they come into direct contact. The use of medical devices must be safe. For this reason, biocompatibility testing in accordance with ISO 10993-1 is mandatory for medical devices in order to assess their biological risk.

    This biocompatibility test ensures that the materials used in the manufactured medical devices do not contain any substances that are harmful to human organisms, thus guaranteeing patient safety and product conformity.

  • Our medical devices i3 ONE, i3 TWO connect and i3 TWO direct are biocompatible in accordance with ISO 10993-1.

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Christoph-Seydel-Straße 1
01454 Radeberg
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Theodorstraße 41P
22761 Hamburg