The aim of the health and safety legislation is to prevent employees (or members of the public) becoming ill or being injured in the workplace. Because of this it has become the responsibility of the employer to provide a satisfactory working environment, no matter how small the business (including the self employed).
The bodies that manage and enforce the laws on health and safety are the Health and Safety Executive (HSE) and your local authority. Essentially the HSE manages factories, farms, building sites, etc, while the local authorities manage offices, shops, catering, hotels, etc. If you employ anyone then you will likely have to register your business and you will have to have employer's liability insurance (and display the certificate). You will also have to display the health and safety law poster if you employ any staff, and report any injuries or accidents at the workplace.
The duties of an employer for health and safety can be summarised as:
• All employers and self-employed people have to assess risks at work
• Employers with five or more employees should have a written health and safety policy
• Employers with five or more employees have to record the significant findings of their risk assessment
• Employers have a duty to involve their employees or their employees' safety representatives on health and safety matters
• Employers have to provide free health and safety training or protective equipment for employees where it is needed