Class Action: when parents' fears stand in the way of a child's school trip

Day trips and residential trips or "camps" are increasingly being used by schools to extend and enrich the curriculum. It is entirely natural for parents to be anxious, especially about the residential trips, which take their precious offspring away from home for several days. Some parents feel out of control if they are not there to supervise their children personally outside the relatively safe school environment. In fact, some parents are more nervous than the students themselves. Others, however, are delighted at the prospect of a few days of freedom.
You haven't mentioned the specific insecurities these parents have, but whether it is a cultural trip or an adventure camp, local or abroad, no trip is ever completely free of risk. However well planned, accidents can happen.
The key is careful preparation. Be assured that schools take the health and safety of students very seriously. Many teachers are first-aid trained nowadays, and the risk assessments they conduct are extensive, taking careful consideration of any potential hazards and how they can be avoided. Usually, trip leaders organise a pre-trip visit so that facilities, activities and staff are thoroughly vetted and checked.
Camps are generally held at sites that routinely provide all the basic requirements. Qualified professional instructors often lead adventure-type activities such as high rope courses, archery and rock climbing. The team of school staff will usually include experienced teachers and often a senior manager. Many schools mandate a generous ratio of adults to children, and group sizes tend to be even smaller if the trip is abroad. These adults include responsible parents who are suitably briefed in advance.
Has the school offered to run an informational meeting for parents? This can go a long way towards putting parents' minds at rest; the more they know about the itinerary and supervision arrangements, the more faith they have in the whole operation. You could encourage these parents to have a word with the teacher in charge to ask questions and voice their concerns.
It would be a great shame for your daughter's friend to miss out on a potentially life-changing experience. These trips are invariably worthwhile, and this type of learning experience cannot be replicated in the classroom. New relationships can also develop with peers who did not previously bond.