Bill McGregor, general secretary of the Headteachers' Association of Scotland, said that, because of the time it would take to read through pages and pages of new regulations, there was a danger that "folk would lose the notion" of running school trips.
Mr McGregor also called for clarification of some of the guidance, such as a reference to 24-hour supervision on overnight excursions. "What is supervision? Does someone have to sit up all night outside the hotel bedrooms in case someone goes walkabout?" he asked.
"A lot of people have run trips for years because they gave the kids a great experience, because they built relationships with the pupils and because they liked doing it. The focus has been on, 'I like doing it', but with 20-odd bullet points, who's got time to do this?"
Mr McGregor added: "On the one hand, the guidelines open with exactly the right message - that participants can derive a great deal of educational benefit. But on the other hand, it is a daunting document for something that is essentially a voluntary activity, and that is my fear."
Nigel Scriven, chairman of the Scottish Advisory Panel for Outdoor Education, said it was important to put in place appropriate in-service training to allay fears about implementing the new guidelines. "We have to make sure that there are navigation routes through all the piles of documentation so they can easily locate all the information they need," Mr Scriven said.
He welcomed the guidelines, saying they were somewhat overdue but that they broke new ground because they applied to all council services for children.
"The challenge for local authorities and schools is to deal with risk assessments in a way that does not create a mountain of paperwork and a barrier to school trips.
"The burden placed upon the school or school leader must be reduced to a level where it is risk-specific to that leader taking that particular group of kids to that particular place on that particular day."
Alan Blackie, director of education for East Lothian, who sat on the working group which prepared the guidelines, doubted that they would make the planning of trips "hugely more complicated" as health and safety and risk assessment elements should already be in place.
Mr Blackie pointed to the need for robust procedures after the case of Dugald Campbell, headteacher of Ratho primary near Edinburgh, who was fined pound;750 last year, thereby getting a criminal conviction, after a six-year-old nearly drowned on a school trip to North Berwick beach.
Mr Campbell, who did not take part in the excursion, pleaded guilty to putting children at risk of drowning because he had failed to make proper risk assessments for the trip. Edinburgh City Council was fined pound;3,500 in that case after admitting putting children at risk.
Ewan Aitken, the local authorities' education spokesperson, said councils planned to hold discussions with the Executive about the need for new legislation to reduce the risk of litigation.
But he commented: "We are in danger of creating a generation of risk-averse children who become so protected that they suffer. You get nowhere in life if you become frightened of the day you never see.
"School trips are no more or less dangerous than walking to the shops or many of the activities undertaken by children with their families at the weekend."