Drykeeper: Frequently Asked Questions

Approximately −30 °C to +90 °C. Drykeeper mini’s adhesive tape is recommended for −15 °C to +80 °C.

Drykeeper is compliant with theREACH Regulation and RoHS Directive. Since it is not an electronic device, Drykeeper is notsubject to the WEEE Directive. If you need any certificates of non-use, please issue a request to our technical staff or use the inquiry form.

Yes. Drykeeper has an established track record in outdoor infrastructure and equipment enclosures.

No. It absorbs moisture at high humidity and releases it at low humidity, stopping automatically before condensation can form.

No. Drykeeper maintains humidity within a condensation-free range, rather than controlling to a precise RH value.

Yes. Drykeeper FR is certified to UL 94 V-0. It is available on request

See our selection procedure or contact us with your question for

DryKeeper uses a maintenance-free polymer absorber with a typical service life of up to 10 years. It buffers internal humidity by absorbing water vapour when relative humidity is high and releasing it when conditions dry, helping to stabilise enclosure humidity in the 50–60% RH range.

Yes. Drykeeper can be cut with scissors or a cutter knife, and it can also be processed using standard Thomson die cutting.

Temporary deformation does not change the product’s characteristics. However, if oil or contamination transfers onto the material during pressing, it may reduce moisture absorption/release performance.

Yes, bending or folding does not change the basic absorption/release behaviour.
However, if folding places it in a tight space that blocks airflow and reduces contact with air, it may not perform effectively.

Drykeeper mini uses Nitto acrylic double-sided tape No. 5000NS. For adhesion data, refer to the manufacturer’s published specifications.
As a reference, internal testing at 80°C / 80% RH for 500 hours showed no detachment on: PC, ABS, FRP, SUS (stainless steel), aluminium, steel. See Nitto datasheet

Drykeeper is made from superabsorbent polymer (similar to materials used in diapers) and synthetic rubber. It does not contain substances regarded as environmentally hazardous in this context.

Unlike inorganic desiccants such as silica gel that may be treated as industrial waste in some settings, Drykeeper can be disposed of as general waste (follow local rules if your site has specific disposal procedures).

Intermittent humid air ingress can increase the moisture load. However, when outside relative humidity drops (often during daytime temperature changes), Drykeeper releases moisture—and the flow of drier outside air can help that release.
Exceeding capacity is considered unlikely except in special environments such as tunnels or coastal/sea-adjacent locations with persistently high moisture.

No. Drykeeper is designed to keep humidity within a range that prevents condensation, not to maintain a precise RH setpoint.

Yes. It can be used in combination with other desiccants, and no cases have been confirmed where combined use degrades Drykeeper’s performance.

No. If external humidity is low, Drykeeper will naturally be in a moisture release state. Sun-drying is not required.

If dust clogs the nonwoven fabric, performance could be reduced. In dusty environments, consider placement or shielding that maintains airflow without allowing heavy dust build-up.

Examples include infrastructure and equipment such as:

• Road: ETC equipment, display boards, parking payment machines
• Rail: level crossing barriers, display boards
• Airports: runway guidance lights
• Electronics: surveillance cameras, servo motors

Testing by leaving the product for over one month at room temperature in a high-humidity environment, and no mould growth was observed.

Standard Drykeeper is not certified for flame retardancy. Drykeeper FR is certified to UL 94 V-0.

Depending on thequantity, FEPS may be able to provide a custom size. Please contact FEPS (minimum approx. 35m² for an order).
Furthermore, cutting and punching does not affect the moisture absorption and desorptionperformance of Drykeeper. Therefore, customers may cut/punch the purchased Drykeeper to suittheir needs. However, FEPS provides no guarantees in the event of any issues/failures arising fromcutting or punching performed by customers.

(Note)
The blue non-woven fabric that contains Drykeeper has a water repellent effect. Thisprevents the body of Drykeeper from expanding due to direct contact with water in theunlikely event that condensation occurs. Please use caution when handling Drykeeperwithout the non-woven fabric after cutting.