Stop Work is everyone’s right and everyone’s obligation to help protect yourself and/or a co-worker. When you see something that needs to be stopped, we should all feel comfortable in stopping the work. You should keep in mind when invoking a ‘stop work’, that what you see may not be apparent to the person/people doing the work so it is important to let people know why you are stopping work.  For example “I need to stop this work for a second to keep someone safe because I saw ______”. Don’t let stop work come across as you are right and he/she is wrong. By doing this you are likely to get a negative reaction and not invoke a a learning event and a change in behavior. If stopping work is viewed as a genuine concern for health and safety, it will be appreciated every time. This is the only way we can create a culture of people looking out after each other.