We have not made any estimate of the number of teachers who may not have had a Criminal Records Bureau check. All teachers currently working in the school workforce will have had either an enhanced CRB disclosure or a check against the old police records system if they were in post prior to the introduction of the CRB, and all teachers will also have been checked against the list of those barred from working in educational establishments (List 99). All new appointments, both teaching and support staff, in the school workforce now require an enhanced CRB disclosure under the terms of the School Staffing (England) (No2) Regulations 2006, and those regulations also require schools to maintain a record of the vetting checks they have carried out on their staff. From November 2010 all new appointments to the school sector will have to register with the new vetting and barring scheme, and all existing staff in school will have to register by 2015. The ISA registration process incorporates a CRB check. The CRB collect some statistics on the volume of checks being made in the education sector on a monthly basis.
However, this is for all school staff not just teachers, and some teachers will have had more than one check if they are involved in supply work or work for more than one employer so we would be unable to make an estimate of the number of teachers who have not had a CRB check.