There have been earlier posts on this forum regarding the dangers of socket covers. The problem was originally highlighted by the FatallyFlawed campaign (a group of professional engineers, doctors and child-care professionals).
Are you aware that subsequent to that Which? did a partial test of socket covers and also found some problems?
As a result of the original study Ofsted has ceased to demand the use of socket covers, but so far the Government has done nothing to either ban their sale or introduce regulations to ensure that they are safe.