When organising an educational visit you will also need to think about the health and safety implications and procedures for dealing with emergencies, should they arise, including how to communicate with the school (see also Planning/Communicating with parents/Communication and educational visits).
For detailed information on planning and leading educational visits, including emergency procedures, please refer to the DfES good-practice guidance:
All of these can be downloaded from http://www.teachernet.gov.uk/visits.
The guidance does not seek to replace local or other professional guidance or regulations. Where appropriate, LEAs should be the first source of such advice.
The advice contained on this site should not be taken as an authoritative interpretation of the law.
That is a matter for the courts.