According to recent studies, the key challenges that reduce the effectiveness of existing handwashing technologies include unreliable access to water and soap; lack of ownership, O&M at the community and institutional level; the prioritisation of distributed or purchased soap for laundry, bathing and dishwashing over handwashing; insufficient drainage around handwashing stations and handwashing stations that break easily or are difficult for some to use.

The recommended minimum handwashing water quantity at public toilets is 1-2 litres per user per day. If the supply is piped, each handwash can use 500 ml of water, though water-saving taps can decrease this volume to 100-250 ml. If piped water is unavailable, alternative ways of providing a constant water supply must be provided (such as using rainwater or establishing rotas for refilling water containers). The minimum amount of soap required for personal hygiene - including handwashing - is 250 grams per person per month. Soap is usually provided in the form of bars, but liquid soap or soapy water may be an alternative, particularly during pandemics like COVID-19 (to avoid shared touch points on soap bars or lack of supplies). If neither water nor soap is available, alternative products may be used (such as a 0.05% chlorine solution if chlorine is sufficiently available and does not compete with other uses such as drinking water disinfection. Soap and a 0.05% chlorine solution should not be used together).

Handwashing facilities should be designed to be inclusive and accessible to all adults and children, including persons with disabilities. All disabilities affecting the targeted population should be assessed, e.g. visual, physical or mental impairments. Facilities should be durable, robust, easy to clean, transport and construct. A wide variety of technical options exist, ranging from simple, low-cost facilities such as buckets with a tap (e.g. Oxfam bucket), Tippy Taps or group handwashing facilities (such as the WASHaLOT) to more robust permanent handwashing stations with tap(s). Drainage of effluent is important to keep the area around the handwashing facility clean and hygienic, not muddy and flooded. Greywater can be collected in a bucket or discharged into open drainage channels or a closed sewer, or directly into a mains sewer.

Handwashing facilities near women’s toilets should be located within the toilet stall, if possible. This supports dignity and privacy when washing hands after handling used menstrual products, as well as encouraging safe menstrual hygiene practices. Women and girls should not be deterred from changing or washing pads, changing tampons or emptying menstrual cups because of a lack of handwashing facilities within the toilet stall. Ideally, handwashing facilities should be designed so that they can be operated hands-free to prevent cross-contamination (e.g. using self-closing taps, foot-operated pedals or elbow-operated levers). However, for people with disabilities (e.g. wheelchair users) hand-operated options may still need to be considered. Self-closing taps may be an alternative: they save water, are more durable and people do not have to touch the tap with their fingers to turn the water supply on and off. Handwashing facilities must be inclusive; children and people with reduced mobility (such as persons with wheelchairs) must be able to reach the handwashing facilities to use them. Adequate lighting must be provided so that people can use the facilities safely at night. Attractive looking handwashing facilities may encourage use T.4 and involving users in their design and decoration may increase familiarity and acceptance. Information, Education and Communication materials T.19 such as posters or paintings on handwashing techniques should be available at handwashing stations and be easy to understand for those with limited literacy.

Hygiene promotion (HP) should also encourage adequate hand drying after handwashing as damp hands can re-contaminate quickly and potentially spread far more bacteria than dry hands. The most pragmatic solution is air drying by simply waving hands after handwashing until they have dried.