OASSAY combines multiple water-treatment technologies in one compact filtration system.

A 0.1 μm hollow-fiber membrane physically filters bacteria, parasites, microplastics, sediment, and other fine particles.

Our NanoFlex activated carbon helps reduce unpleasant tastes and odors while also helping adsorb contaminants such as PFAS and certain heavy metals.

In addition, electrostatically charged filtration media help attract and adsorb virus particles as water passes through the filter.

Together, these technologies provide broad water protection in a portable bottle designed for international travel, outdoor exploration, and adventures where the safety of your water source may be uncertain.

For detailed filtration performance and laboratory test data, please visit our Safety & Performance page.

OASSAY is designed for freshwater sources where water quality or safety may be uncertain, whether you are traveling internationally, exploring the outdoors, or simply encountering unfamiliar water away from home.

This includes both urban travel water and natural outdoor water sources around the world — from hotel tap water in another country to mountain streams, lakes, wells, springs, and backcountry water sources in North America, Europe, Asia, Africa, Latin America, and beyond.

Different water sources may present different risks:

• Hotel, hostel, and local tap water
  Depending on local treatment, plumbing, storage tanks, and distribution systems, potential concerns may include bacteria, viruses, sediment, unpleasant tastes and odors, and contaminants introduced through aging infrastructure or storage.
• Rivers, streams, lakes, and reservoirs
  These may contain bacteria, viruses, parasites, microplastics, sediment, and contamination from wildlife, livestock, human activity, or upstream wastewater.
• Mountain and backcountry water sources
  Even clear-looking streams and lakes may contain microorganisms introduced by animals, hikers, campsites, or upstream activity. Clear water is not necessarily microbiologically safe.
• Wells and groundwater
  Depending on local geology and surrounding activity, groundwater may contain microorganisms, certain heavy metals, PFAS, or agricultural contaminants.
• Natural springs
  Spring water may look exceptionally clear but can still be affected by microorganisms or contamination entering groundwater or surrounding soil.
• Rainwater and stored water
  Water collected from roofs, tanks, cisterns, or other storage systems can pick up bacteria, sediment, debris, and other contaminants during collection and storage.
• Water during emergencies or infrastructure disruptions
  When normal water systems are interrupted, water quality can become less predictable and the risk of microbial contamination may increase.

OASSAY can be used with a wide range of freshwater sources, including uncertain tap water and untreated freshwater encountered while traveling, hiking, camping, overlanding, fishing, paddling, or exploring outdoors.

For very cloudy or sediment-heavy water, allowing the water to settle or pre-filtering it first can help maintain flow and extend filter performance.

OASSAY is not designed to desalinate seawater or brackish water. Water known to be heavily contaminated by industrial chemicals, toxic spills, or severe chemical pollution should also be avoided.

Different parts of the OASSAY filtration system are designed to address different types of contaminants:

• Viruses — electrostatic adsorption
• Bacteria — 0.1 μm hollow-fiber membrane
• Parasites and protozoa
• Microplastics and fine particles
• PFAS and certain heavy metals — adsorption through NanoFlex activated carbon
• Unpleasant tastes and odors — NanoFlex activated carbon

For specific removal rates and laboratory test results, please visit our Safety & Performance page.

With proper care and regular backwashing, an OASSAY filter can process a substantial amount of water.

For hygiene and consistent filtration performance, we conservatively recommend replacing the cartridge after approximately 500 liters of filtered water or 6 months of use, whichever comes first.

For context, 500 liters is equivalent to filtering roughly 2.7 liters every day for six months.

Like other filtration media that remain regularly exposed to water, extended use in a wet environment can increase the possibility of microbial growth inside the cartridge over time.

Our 500-liter / 6-month recommendation is therefore a conservative hygiene guideline, rather than an indication that the filter suddenly stops working once it reaches that point.

Actual filter life can also vary depending on source-water quality, sediment levels, frequency of use, and maintenance.

There is no fixed backwashing schedule because membrane clogging depends largely on the quality of the water you filter.

The easiest rule is:

When you notice a significant decrease in flow, it is time to backwash.

Backwashing pushes clean water through the hollow-fiber membrane in the reverse direction, helping flush out sediment and particles trapped inside the membrane and restore flow.

We also recommend backwashing after filtering particularly cloudy or sediment-heavy water and before long-term storage.

Always use clean water for backwashing.

OASSAY is designed to filter water between:

0°C and 45°C (32°F–113°F)

This range covers most cold, cool, and room-temperature freshwater encountered during travel and outdoor use.

Do not filter water above 45°C / 113°F, as excessive heat is outside the recommended operating range of the filtration system.

Water below 0°C / 32°F should also not be filtered through the cartridge.

Because OASSAY stores untreated water inside the bottle and purifies it as you drink or dispense, basic hygiene is important.

To reduce the risk of cross-contamination:

• Treat all water inside the bottle as untreated water until it has passed completely through the filter.
• Keep the drinking outlet and clean-water side of the filter away from untreated water.
• Avoid touching the drinking outlet with dirty hands or placing it on contaminated surfaces.
• If untreated water contacts the drinking outlet, rinse and clean the outlet with safe water before drinking.
• Empty and clean the bottle regularly after use.

Following these simple practices helps keep untreated water separated from the water you drink.

After use, empty any remaining untreated water and clean the bottle regularly.

Before long-term storage:

1. Backwash the filter with clean water.
2. Empty the bottle completely.
3. Allow the bottle and components to dry thoroughly.
4. Store the product in a clean, dry place.

Keeping the bottle, drinking outlet, and filtration components clean helps maintain hygiene and long-term performance.

Yes. The OASSAY bottle and applicable bottle components can be cleaned in a dishwasher.

However:

The filter cartridge must always be removed before dishwasher cleaning and must never be placed in the dishwasher.

Do not expose the filter cartridge to high-temperature dishwasher cycles or dishwasher detergent.

OASSAY currently ships to most countries and regions worldwide.

Orders of US$39 or more qualify for free shipping to supported destinations.

Shipping times may vary depending on the destination, local customs procedures, and the shipping service available in your region.

If your country or region is not currently available at checkout, please contact us at:

support@oassay.com

We’ll be happy to check available shipping options for you.

Every OASSAY product is backed by a 2-year warranty and dedicated human customer support.

If you experience a product issue or have questions about use, maintenance, filtration, replacement parts, or shipping, you can contact us anytime at:

support@oassay.com

You can also message us directly through our official social media accounts.

We take after-sales support seriously and will always do our best to help resolve any issue with your OASSAY product.