Unless gloves are worn when handling the ice, whatever bacteria are on the user’s hands will get transferred to the ice – this includes faecal matter too.
The tests which AquaCert perform are the same as for ordinary drinking water since you want to know that when the ice melts it is the same quality as drinking water.
Legionella is seldom a problem with Ice Machines since the cold temperature prevents the bacteria multiplying. Unfortunately, they are not completely without risk, there are several cases where people have choked on ice cubes containing small numbers of legionella. This type of choking, known as aspiration, allows the bacteria to enter the lungs and then multiply, for one person it was fatal.