Regulations, codes of practice and guidance

Regulations lay down minimum legal standards. Breaches of regulations constitute criminal offences that can lead to enforcement action (e.g. prosecution, imposition of fines). Most health and safety regulations are made under the Health and Safety at Work etc Act by the Secretary of State after consultation with HSC. They often implement EC Directives that are aimed at protecting employees and others.

Approved codes of practice have quasi-legal status. Duty holders must comply with them or be able to show that the chosen means of control are equally effective. They are approved by the HSC with the consent of the Secretary of State and that their purpose is to provide practical interpretation of legal requirements in specific areas. Although failure to comply with any provision of an ACOP is not in itself an offence, the failure may be cited in court in criminal proceedings as proof that there has been a contravention of the regulation to which the provision relates.

HSE guidance has no formal legal standing, is generally more informative and practical than an ACOP, and is intended to give advice on good practice.

Example
REGULATION
regulation 7 of the workplace act states during working hours, there shall be a reasonable working temperature

ACOP
the ACOP states the minimum temperature will be 16 degrees celsius unless physical work is involved, then its 13 degrees

GUIDANCE
HSG 194 (thermal comfort in the workplace)
gives guidance on possible solutions to maintain the welfare of employees working in low temperatures.

*Some times the regs cannot be followed exactly, ie minimum temperature at work, so the acop provides the details and guidance shows you how to comply in other ways, such as supplying thermal clothing, boots, limiting time in cold areas, supply of a room to get warm etc.*

Reference

Also, well summarised by HSE here