The "Nonwoven Dispersibility Test" for Flushable Wet Wipes — A Detailed Look at the International Mainstream Method (EDANA/INDA)

I. The Seven-Step Test: A Full-Chain Simulation from Toilet to Treatment Plant

Before earning a "flushable" label, a product must sequentially pass all seven of the following tests — failure in any single one results in a "non-flushable" designation:

1. FG501 Toilet and Drain-Line Clearance Test: Simulates whether the wipe, after being flushed, can smoothly pass through household and municipal drainage pipes without causing snags or blockages.

2. FG502 Slosh Box Disintegration Test (Core Indicator): Places the wipe in a slosh box filled with water and oscillates it at a specific frequency to simulate physical breakdown during sewage conveyance. This is the critical test for whether the wipe can actually "fall apart."

3. FG503 Household Pump Test: Assesses the risk of fragmented fibers passing through a household sump pump, preventing fiber entanglement around the pump impeller.

4. FG504 Settling Test: Measures the settling velocity of fragments in water — too fast, and they accumulate at pipe bottoms; too slow, and they float on treatment tank surfaces; neither is acceptable.

5. FG505 Aerobic Biodisintegration/Biodegradation Test: Simulates whether fiber fragments can be broken down by microorganisms into water, CO₂, and biomass under aerobic conditions (e.g., in wastewater treatment plants).

6. FG506 Anaerobic Biodisintegration/Biodegradation Test: Simulates degradation under oxygen-free conditions, such as in septic tanks.

7. FG507 Municipal Sewage Pump Test: Final verification that fragments can pass through large municipal sewage pumps without causing abnormal power spikes.