The announcement comes after bosses at Manchester Airport were warned by civil rights group Action on Rights for Children (Arch) over the legal issue of security workers creating indecent images of children.
"We certainly aren't going to break any laws in the process of trying to improve the experience of security at Manchester Airport with a voluntary trial," the Telegraph quoted a Manchester Airport spokeswoman as saying.
"Experts in child protection have told us that this is a grey area. On this basis, if these experts tell us that there might be a problem then we'll work with them to establish a definitive position.
"In the meantime no under 18s will participate in the trial when adult passengers start being invited to take part in a couple of weeks," she added.
Arch national director Terri Dowty said: "It's not right to put the machine operators in the position where they are being asked to break the law.
"This is not about whether we think the scanner is a good idea or a bad idea. It's just not lawful and falls under the terms of strict liability.
"Under present legislation the taking of images of children in this way cannot be done."