IWSFG Flushability Specifications

Products that meet the IWSFG flushability specifications are unlikely to cause harm to wastewater conveyance systems or treatment plants.  The IWSFG flushability specifications are available for use by product manufacturers, governmental organizations, and other entities that want to determine if products that are flushed are safe for wastewater infrastructure.

The three publicly available specification (PAS) documents together describe the the criteria that a product should meet to be compatible with being flushed down a toilet.  PAS 1 outlines the five criteria for a product to be labeled flushable: environmental protection, toilet and drain line clearance, disintegration, settling, and biodisintegration.  PAS 2 provides key definitions used in the specifications.  PAS 3 details the disintegration test procedures, since this is the only flushability test that is not effectively defined by other published methodologies.

The IWSFG PAS documents were first published in 2018, with updates made in November 2020.  The 2020 versions are available below in English (other languages may be available in the future). It is expected that the IWSFG PAS documents will be updated in 2023, if you would like to provide information to be considered in the update to these documents please send directly to staff@iwsfg.org.

2020 IWSFG Flushability Specification Documents

IWSFG PAS 1 – Criteria for Recognition as a Flushable Product

IWSFG PAS 2 – Terms and Definitions for Determination of Flushability

IWSFG PAS 3 – Disintegration Test Methods – Slosh Box

2018 IWSFG Flushability Specification Documents

A summary of the 2018 IWSFG flushability specifications, including a comparison to other flushability guidelines, is available here.  The PAS documents are available below in English, Japanese, and Spanish. Templates for recording results of the disintegration test described in PAS 3, are available below in English.

IWSFG PAS 1 – Criteria for Recognition as a Flushable Product: English, JapaneseSpanish

IWSFG PAS 2 – Terms and Definitions for Determination of Flushability: English, Japanese, Spanish

IWSFG PAS 3 – Disintegration Test Methods – Slosh Box: English, Japanese, Spanish

PAS 3, Annex 7 Report Template

PAS 3, Annex 7 Picture Report Template

To ensure that the flushability specifications are both realistic and accepted worldwide, the IWSFG published two draft versions for public comment.  Extensive comments were received from many organizations, and the IWSFG reviewed and addressed all comments.  Draft versions of the IWSFG flushability criteria, the public comments received, and IWSFG response to comments are available at the following links:

First Draft – July 2017

Second Draft – January 2018  


The effectiveness of the PAS documents in protecting sewer networks has been recognised in a recent legal settlement with the City of Charleston, South Carolina, and the documents are being considered by a number of water utilities in the United States and Canada for use in sewer bylaws. The current status of the PAS documents is that they are intended as a Code of Practice for manufacturers to adhere to. They are also forming part of a proposal to the International Standards Organisation (ISO), seeking to develop an internationally agreed Standard for material suitable for toilet disposal, although this will take several years to complete.

In the interim, the IWSFG supports manufacturers adhering to the PAS documents as part of a voluntary Code of Practice. Manufacturers that wish to self-attest that they have passed all of the PAS tests may do so and use the IWSFG flushability logo. Noting that in doing this, the company is making a public claim that it meets the IWSFG PAS criteria. These tests may be independently verified at any time by consumer advocacy groups and government agencies in the jurisdictions where the products are sold. Therefore, when undertaking the testing we suggest that you use accredited third-party laboratories – as you have done with SGS-IPS or CTP. The IWSFG would gratefully appreciate any results that you are able to share with our organisation.