If the question is seeking legal advice then I think you need to look elsewhere. I am not a lawyer.
There are laws and other regulations etc about working conditions, workplaces, handling of equipment and goods and so on. (Think of food handling, or being careful with dangerous chemicals.) These rules mean the employer must do some things and must not do others. The text in bold says the employee must cooperate with the employer to ensure that the rules are not broken.
In answer to a comment seeking clarity on the words "or any other person" from the bold text in the question. I believe them to refer to people working for the regulatory or enforcement authorities, people whose job is to check that a business (and thus an employer and their employees) are following the rules. Basically if a police officer or a food inspector or an official inspector from some other relevant field visits visits, you must cooperate with them. I think you are allowed to check that they have the correct permissions and documentation before helping them.
Whilst I have said "business", "employer" and "employee" I think that in the UK the various rules extend much wider than just businesses. For example, the priest at a church probably has to obey all the rules that apply to business premises, to ensure a safe environment for the congregation.