Anti-loitering devices which emit a piercing sound only young people can hear were installed in train stations without a risk assessment.
ScotRail is under fire for agreeing to place the “absolutely torturous” devices - nicknamed “mosquitos” - which make a sound only audible to those under 25, at two of its stations.
The operator said they were aimed at cutting anti-social behaviour after the RMT union said staff had encountered a “surge in violence” at stations.
But young people, who say the high-frequency noise is “unbearable”, are demanding ScotRail get rid of them via the Scottish Youth Parliament, and Scotland’s Children’s Commissioner Bruce Adamson says the devices are a breach of children’s rights.
Now it can be revealed ScotRail - which is allowing staff to use the devices at Helensburgh and Hamilton - did not explore what impact the devices could have via a risk assessment.
Labour MSP Monica Lennon, the party’s equalities spokeswoman in Holyrood, said people with disabilities could have an adverse reaction and has called on Nicola Sturgeon to intervene.
She said: “I’m very disappointed that high-level talks between police representatives and Scotrail have resulted in this draconian measure, which is no substitute for community policing.
“The recent reports of anti-social behaviour and disorder are troubling and the police must get on with policing.
“What mustn’t be allowed to happen by highly-paid officials at Scotrail and elsewhere is for our community to be demonised and divided. That’s exactly what the Mosquito does.
“I’m very concerned that Scotrail marched ahead with this without even carrying out a risk assessment. And there’s been no consideration given to the impact of the high-frequency noise on people with autism or disabilities, or indeed children and young people in general.
“The Scottish Government needs to get a grip on this awful practice.”
ScotRail said the devices would only be used by its staff when it was “justifiable and proportionate” but admitted no risk assessment had been carried out.
David Lister, for Scotrail, said: “The use of the device has to be justifiable and proportionate and deactivated when the youths have dispersed
“Staff need to have an awareness of the demographic of other members of the public in the vicinity of the device. If there are travelling passengers under the age of 25 including young children and babies who are likely to be impacted by the device whilst they wait for their train, the device should not be activated, and British Transport Police contacted to attend to deal with the youths responsible
He added: “No risk assessment has been carried out. The sound omitted from the device is just out of the range of an adult’s hearing, which is why it only affects people under the age of about 25. The sound is recognised as being harmless, not loud or painful, but is annoying after a short period of time.”
Amy Lee Fraioli, chair of the Scottish Youth Parliament, described her experience of the device at Hamilton in a BBC interview.
She said: “I was waiting there for over 20 minutes and the noise was absolutely torturous. It makes young people feel as if their presence is nothing other than a nuisance and that’s obviously not the case.
“It’s so uncomfortable. It’s really high pitched. It starts to give you a sore head when you’re standing there.
“It got to the point that I was ready to leave the train station, when the train came. It was unbearable.”
The Children and Young People’s Commissioner for Scotland, Bruce Adamson, has intervened and branded the devices a “disproportionate and degrading” breach of children’s rights.
Adamson said: “International human rights bodies, and my office, have long called for these devices to be banned.
“The use of such devices is a breach of children’s rights to go about their lives free from discrimination in a healthy and safe way when they use public transport, visit shops or meet their friends.
“These devices are a disproportionate and degrading approach that acts without discrimination, causing discomfort to any children and young people who encounter them.”