An organisation is guilty of the offence only if the way in which its activities are managed or organised by its senior management is a substantial element of the gross breach of a relevant duty of care owed by the organisation to the deceased. 
A breach of the duty of care owed by the organisation is gross if the conduct alleged to amount to a breach of that duty falls far below what can reasonably be expected of the organisation in the circumstances. 
Senior management means the persons who play significant roles in the making of decisions about how the organisations activities are managed or organised or those doing the actual managing or organising.
Duty of care means the duties owed by the organisation under the law of negligence (for example duties owed to employees or as occupiers of premises).
On conviction an organisation will face an unlimited fine (subject to its means).  There is also the possibility that the organisation could face a remedial order and/or a publicity order.  Failing to comply with a remedial order or a publicity order will be an offence in itself also subject to an unlimited fine.
The introduction of this legislation will not require a major change to the health and safety operations of most businesses.  Rather it will be necessary to continue with good practices such as risk assessments and safe working method statements and to keep health and safety issues high on the agenda at every level of management within the organisation.