Legal notice


Effective / Last Updated: September 29, 2026

1. Product Purpose

OASSAY is a portable personal water purifier bottle designed for international travel, hiking, camping, overlanding, paddling, fishing, emergency preparedness, and other situations where the quality of a freshwater source may be uncertain.

The OASSAY filtration system combines multiple water-treatment technologies:

  • 0.1 μm hollow-fiber membrane for physical filtration of bacteria, parasites, microplastics, sediment, and fine particles.
  • NanoFlex activated carbon to help reduce unpleasant tastes and odors and adsorb certain contaminants, including PFAS and certain heavy metals.
  • Electrostatically charged filtration media designed to attract and adsorb virus particles as water passes through the filter.

OASSAY is designed for use with suitable freshwater sources and should always be used in accordance with the operating conditions and instructions described below.

This product is not a medical device and is not intended to diagnose, treat, cure, or prevent disease.

2. Tested Filtration Performance

OASSAY filtration cartridges have been evaluated through independent laboratory testing.

Laboratory testing has demonstrated performance including:

  • >99.999% removal of bacteria
  • >99.999% removal of MS2 bacteriophage, a widely used virus surrogate in water-filtration testing
  • 99.99% removal of microplastics

Additional testing and technical documentation may be available for other contaminants and filtration characteristics.

Laboratory results are obtained under controlled test conditions. Actual field performance may vary depending on source-water quality, turbidity, sediment levels, water temperature, cartridge condition, flow conditions, maintenance, and correct use of the product.

For detailed laboratory data, test methods, and applicable reports, please refer to our Safety & Performance information or contact us at support@oassay.com.

3. Suitable Water Sources

OASSAY is designed for a wide range of freshwater sources where water quality or safety may be uncertain.

Examples include:

  • Hotel, hostel, and local tap water
  • Rivers and streams
  • Lakes and reservoirs
  • Mountain and backcountry water sources
  • Wells and groundwater
  • Natural springs
  • Rainwater and properly collected stored water
  • Freshwater encountered during travel, camping, hiking, fishing, paddling, and overlanding

Even water that appears clear may contain microorganisms, microplastics, sediment, or other contaminants that are not visible to the naked eye.

OASSAY is not designed for:

  • Seawater
  • Brackish water
  • Industrial wastewater
  • Oily water
  • Water known or suspected to contain severe chemical pollution
  • Water affected by toxic spills or unusually high concentrations of hazardous chemicals

OASSAY does not desalinate water.

If source water is extremely cloudy or contains large amounts of sediment, allow the water to settle or pre-filter it before use. This can help maintain flow and reduce unnecessary clogging of the filter.

4. Operating Conditions

For best performance, use OASSAY within the following operating conditions:

  • Filtration rating: 0.1 μm
  • Typical flow rate: approximately 0.6–0.8 L/min (20–27 fl oz/min)
  • Recommended water temperature: 0–45°C (32–113°F)
  • Recommended replacement guideline: approximately 500 L (132 gal), or 6 months after first use, whichever comes first
  • Unopened shelf life: up to 3 years when stored correctly

Do not filter water above 45°C (113°F) or below 0°C (32°F).

Actual filter performance and usable life may vary depending on source-water quality, sediment levels, maintenance, and frequency of use.

5. Filter Life, Hygiene & Replacement

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

For hygiene and consistent filtration performance, OASSAY conservatively recommends replacing the cartridge after approximately 500 L (132 gal) of filtered water or 6 months of use, whichever comes first.

For reference, 500 L (132 gal) is equivalent to filtering approximately 2.7 L (0.72 gal) per day for six months.

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

The 500 L (132 gal) / 6-month guideline is therefore intended as a conservative hygiene and maintenance recommendation. It does not mean that the cartridge suddenly stops filtering once this point is reached.

Replace the cartridge sooner if it is damaged, contaminated, or no longer performs normally after appropriate maintenance.

6. Backwashing & Maintenance

There is no fixed backwashing schedule because clogging depends largely on the water being filtered.

If you notice a significant reduction in flow, backwash the filter using clean water.

Backwashing helps remove sediment and particles trapped inside the hollow-fiber membrane and can restore normal flow.

We also recommend backwashing:

  • After filtering particularly cloudy or sediment-heavy water
  • Before extended storage
  • Whenever flow becomes noticeably restricted

Always use clean water for backwashing.

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

Before long-term storage, backwash the filter, drain the bottle, allow components to dry as thoroughly as practical, and store the product in a clean, dry place.

7. Cross-Contamination

Water inside the OASSAY bottle should be treated as untreated water until it has completely passed through the filtration system.

To reduce the risk of cross-contamination:

  • Keep untreated water away from the drinking outlet and clean-water side of the filter
  • Avoid touching the drinking outlet with dirty hands
  • Avoid placing the drinking outlet on contaminated surfaces
  • If untreated water contacts the drinking outlet, clean or rinse it with safe water before drinking
  • Clean the bottle and drinking components regularly

Correct handling and regular cleaning are important parts of safe use.

8. Manufacturing Quality Controls

OASSAY filtration cartridges are subject to production and batch-level quality-control procedures.

These controls may include:

  • Integrity and particle-passage testing during cartridge production
  • Batch sampling and microbiological filtration verification
  • Inspection of cartridge structure and filtration performance before release

Production batches are released only after applicable quality-control requirements have been completed.

Detailed quality-control records or supporting documentation may be made available where appropriate.

9. Materials & Compliance Information

OASSAY selects materials used in water-contact components based on applicable food-contact and material-safety requirements.

Depending on the specific product configuration, these may include:

  • Food-grade silicone
  • Titanium components
  • PES hollow-fiber membrane materials
  • NanoFlex activated-carbon filtration media
  • Other food-contact polymers, seals, and structural components

Supporting supplier declarations and third-party test documentation may include references to applicable requirements such as:

  • FDA food-contact requirements
  • EU food-contact material requirements
  • REACH
  • California Proposition 65 material screening

Based on the material documentation and testing currently available to OASSAY, no California Proposition 65 warning is presently applied to the product.

Supporting compliance documentation is available upon reasonable request.

10. Important Safety Information

Laboratory testing provides useful information about filtration performance under defined conditions, but no portable filtration system should be assumed to make every possible water source safe under every possible condition.

Users should:

  • Select freshwater sources appropriate for the product
  • Follow the operating limits described in this document
  • Maintain and replace the cartridge as recommended
  • Follow applicable local water-safety guidance
  • Use additional treatment where local conditions or authorities require it

OASSAY does not guarantee 100% removal of every possible contaminant under all water conditions.

11. Legal Notice & Limitation of Liability

Nothing in this notice is intended to exclude or limit any rights that cannot legally be excluded or limited under applicable consumer-protection law.

To the extent permitted by applicable law, OASSAY is not responsible for loss, damage, or injury resulting from:

  • Misuse of the product
  • Use outside the stated operating conditions
  • Failure to follow maintenance or replacement instructions
  • Use with unsuitable water sources
  • Modification of the product or cartridge
  • Continued use after the filtration system has been damaged

Actual rights and remedies may vary depending on the country or region where the product is purchased or used.

12. Warranty, Returns & Customer Support

Warranty, return, refund, and replacement terms are covered separately in our:

  • Warranty Policy
  • Returns & Refunds Policy
  • Terms & Conditions

If you experience any issue with your OASSAY product, please contact:

support@oassay.com

Our support team will review the situation and assist with troubleshooting, replacement, warranty, or other available solutions.

13. International Use

OASSAY products are used by customers in different countries and environments.

Water-treatment regulations, public-health recommendations, and product requirements may vary between jurisdictions.

Users should follow applicable local water-safety guidance and any instructions issued by relevant local authorities.

14. Updates

OASSAY may update this information as products, test data, specifications, or applicable requirements change.

The version published on the official OASSAY website represents the current version of this information.