If you are talking about the standard basic safety checks on installations, plugs and wiring which schools are required to make on a regular basis, there is no reason why this responsibility should not be given to an employee, who has received the training necessary for the purpose.
It is the head's duty to see that such checks are properly carried out and logged and that includes ensuring that they are done by a suitably qualified person.
If a pupil hits a teacher, is it legitimate for the teacher to return the blow?
I find it hard to imagine any circumstances where this could be excused.
The Secretary of State is currently considering whether it is necessary to redefine the powers of teachers in dealing with pupils who are physically violent, but the general rule, which has applied for many years, remains the best guide.
This is that a teacher is entitled to use such force as may be necessary to prevent a pupil from doing damage to himself, to others or to property and no greater force or restraint than the minimum required to achieve the purpose.
This is essentially a concept of restraint and there is no place in that for the striking of blows. There is certainly no justification for any form of retaliation.
Local residents exercise their dogs on our playing fields, with the resultant health risks for our pupils. Can we prosecute them for this?
The law relating to this problem is now contained in the consolidated Education Act 1996, which states: "Any person who without lawful authority is present and causes or permits nuisance or disturbance to the annoyance of persons who lawfully use the premises (whether or not such persons are present at the time), is guilty of an offence and liable to (a fine)."
The law also lays down that such a person may be removed by a police officer or other authorised person.
This seems to describe your dog-walkers exactly, although you would have to be able to prove that it was the individual's own dog which had been permitted to cause the nuisance. You would not be able to prosecute them just for being there.
It would obviously help if you could enlist the support of the police in dealing with this, although a prosecution may also be brought by a local education authority, someone authorised by them, or by the governing body of a grant-maintained or voluntary-aided school.