11.—(1) Contravention of regulation 4(1), 4(2), 5, 6(1), 6(3), 6(4), 7, 8, 9 or 10 by an employer shall be an offence punishable on summary conviction by a fine not exceeding £2000 or on conviction on indictment by imprisonment for a term not exceeding 2 years or a fine, or both.
(2) Contravention of regulation 4(1), (2), (3) or (4), 5, 6(1), (2), (3), or (4), 7, 8, 9 or 10 by a master shall be an offence punishable only on summary conviction by a fine not exceeding £1000.
(3) Contravention of regulation 4(1), 4(5), 5 or 6(5) by any person shall be an offence punishable only on summary conviction by a fine not exceeding £400.
(4) It shall be a defence for a person charged in respect of a contravention of any of these Regulations, including a person charged by virtue of regulation 12, to show that he took all reasonable precautions and exercised all due diligence to avoid the commission of the offence.