The problem with sinks

Effective handwashing depends on four things happening properly: surface preparation, coverage, dosing and dwell time (to learn more about these four elements click here) but a standard sink setup of soap and water doesn't actually control any of them.

They're controlled by the person standing at it.

Surface preparation depends on how long someone rubs their hands and how thoroughly, which varies from one wash to the next and one person to the next. Coverage depends on technique - whether someone actually gets between their fingers and round their thumbs, or just runs their palms under the water. Dosing depends on how much soap they pump out, which can be a token squirt or a handful and nobody's checking either way. Dwell time depends on how long they feel like standing there, which tends to shrink the busier or more rushed they are.

A sign above the sink or a poster on the wall can tell people what good technique looks like. It can't make sure it happens. Training helps, but training worn thin by a busy shift, a distracted moment or simple habit doesn't hold up wash after wash. None of this means people are careless - it just means a sink puts all four elements in the hands of whoever's using it, with nothing checking that any of them actually happened.

The four elements also lean on each other, so it's rarely just one thing going wrong. More soap won't fix an area someone missed. Standing there longer won't make up for poor technique. Reaching every part of the hand doesn't count for much if the soap's been rinsed off before it's had time to work. An effective wash needs all four at once - not four separate things to get right on their own.

Learn about Meritech's CleanTech automated handwashing stations here.