PHOENIX — State senators gave preliminary approval Thursday to blocking schools from collecting fingerprint data from their students.

State senators voted Thursday to prevent schools from using fingerprint scanners like this to identify students unless they first got specific written permission from parents. (Capitol Media Services photo by Howard Fischer)

 SB 1216 is being pushed by Sen. Karen Johnson, R-Mesa, who fears Arizona schools will be swept up in the nationwide push to force students to identify themselves with fingerprints. She said lawmakers need to step in now, before youngsters have their prints on file — or at least the digital images — which she fears could eventually be used to steal their identities.

 But Johnson did agree to amend her measure to allow “finger imaging’’ if parents provide specific written permission.

 The technology is taking root as schools look for ways to track students. Mike Smith, lobbyist for the Arizona School Administrators Association, said it is particularly useful in school lunch programs, especially for youngsters who qualify for federally subsidized free or reduced-price meals.

 Right now, Smith said, many schools are using a version of credit cards, with a magnetic stripe that can be “swiped’’ through a reader. “Kids lose the darn things,’’ he said. Smith said it also presents problems for schools who have to account for the meals, as it becomes difficult to prove that the student who has the card is the one who is supposed to get fed.

 Marana Middle School is using what’s been labeled “biometric information’’ for about a year and a half. That replaced individual student PIN numbers.

 But district officials said there are no plans to put in scanners at other schools, at least not at the current time. Johnson wants to quash the practice before it spreads. And her fear is not so much how the schools are using the information but what can be done with it, now and in the future.

 She said someone who has a credit card stolen can report that and get a new one.

 Johnson predicted, though, that retailers hoping to stop credit card fraud and make purchases easier for customers will begin allowing them to instead pay with finger scans.

 She acknowledged that the schools do not keep the actual prints on file but instead a digital representation. But Johnson said anyone who has access to that information can copy the unique set of numbers assigned to a specific person and then find a way to use that same information to make purchases or steal identity.

 And fingerprints, she said, are forever. The future Johnson predicts may already be here: A company known as Pay By Touch started enrolling restaurants, grocery stores and other businesses since 2002.

 But consumers and merchants may not be quite ready for it. Solidus Networks Inc., the company’s parent, announced earlier this month it was halting its biometric processing of bills “based on lack of funding and current market conditions.’’ Some personal computers, though, come with fingerprint scanners which can be used instead of passwords.