You have to learn to use the washer in a proper manner. Reading the manual that goes with the unit is essential. In case you have any doubts, it is important to ask someone with a lot of experience. You have to minimize all the dangers that may come with them.
Many people are concerned that the pressure washers are not as safe as they would like. It is true that the washers are powerful, and you need to be careful while you use them. You can see here all the issues that there might be when you use them.