The ease with which a user can satisfy a desire for safe drinking water.


The volume of treated water that a user can dispense at a given time.


“Base of pyramid”—low-income consumers.


A third-party attestation that a product is in compliance with characteristics defined in a standard. Certification is distinct from supplier declarations or laboratory test reports.


A consumer appliance (versus a fast-moving consumer good [FMCG]).


Performance of an HWTS product in regular use.


Performance of an HWTS product under controlled (experimental) conditions.


“Extended user testing”—a six-month observational household study of consumer interactions with HWTS durable devices.

flow rate

The volume of treated water that can be dispensed in a given time.


“Fast-moving consumer good”—single-use packages of a water treatment product.

head height

Height of the column of water above filter or treatment elements.


Household water treatment and storage.

platform interface

A standardized receptacle component that enables a variety of water treatment cartridge (filter) designs to be used in a single HWTS device.

platform strategy

A product development and marketing strategy that allows separate manufacturers to create HWTS enclosures and HWTS treatment cartridges, with the goal of encouraging innovation and competition between manufacturers.

pour-over height

The maximum height a container of untreated water must be raised (above floor level) in order to fill an HWTS device.


A consensus document that is approved by a recognized body that provides rules, guidelines, and characteristics intended to optimize product attributes in a given context. Standards compliance is normally voluntary, unless required by law or regulation.


“Total dissolved solids.”

user assistance

Affordances such as product labels, shapes, colors, or graphics that facilitate correct and safe use of an HWTS product.

wait time, or processing time

The time required for an HWTS device to produce a given quantity of safe drinking water.

  • Start = introducing untreated (raw) water to the device.
  • Stop = when a given quantity of treated water is available for dispensing.