You must get help from a competent person to enable you to meet the requirements of health and safety law.
A competent person is someone who has sufficient training and experience or knowledge and other qualities that allow them to assist you properly. The level of competence required will depend on the complexity of the situation and the particular help you need.
When getting help, you should give preference to those in your own organisation who have the appropriate level of competence (which can include the employer themselves) before looking for help from outside. You must consult health and safety representatives in good time on the arrangements for competent help.
Find out more in The Management of Health and Safety at Work Regulations 1999.