The Crown Prosecution Service has been sent police files on the death of Herve Bola, 16, and could bring charges against the youth workers who led the holiday in the Brecon Beacons, in Wales.
Last week an inquest jury in Neath, south Wales, returned a majority verdict of 7-2 that Herve had been unlawfully killed.
The National Union of Teachers has demanded a judicial review, branding the verdict perverse.
The CPS said that it looks, as a matter of procedure, at all unlawful killing verdicts returned by an inquest.
But its move has fuelled teachers' fears that they could face criminal charges if a child in their care dies or is hurt on a school trip.
Nonetheless, Gethin Lewis, secretary of NUT Cymru, has advised staff to carry on taking trips. He said: "Our position has always been that teachers should still take pupils on school trips despite the current blame culture."
The National Association of Schoolmasters Union of Women Teachers said the verdict justified its policy of advising members not to take pupils on trips.
Herve, who could not swim, died after jumping into a swollen river during the course organised by the London borough of Redbridge in July 2002.The inquest heard youth worker Daniel Brown had challenged boys to jump into a 15-foot rockpool.
Anna Brychan, director of the National Association of Head Teachers Cymru, said the verdict was worrying. "Trips can be so valuable for pupils, and this high- profile case cannot have helped reassure teaching staff," she said.