Can someone with GradIOSH qualification be qualified as NEBOSH certified trainer?

In my opinion anyone can teach a NEBOSH course, despite the previous post, NEBOSH don't care. You can even teach yourself or have a computer to teach you also (E-Learning).

However, to be a NEBOSH accredited centre, then that is a different matter.

All the info you need is on the NEBOSH website.
Go to The Course Providers Tab and then you will get the following page . On the right hand bottom, there are zip files for all NEBOSH Courses that havce all the info for course providers, including a handbook that appearts to be standard one for all courses.

https://www.nebosh.org.u...lt.asp?cref=115&ct=2

Guidance on applying for Part B accreditation
Applicants should obtain a copy of the Guide to the qualification they intend to offer from the NEBOSH website for full details of the syllabus content and assessment requirements.

i) Tutorial teams

NEBOSH needs to be satisfied that the course provider has a teaching team comprising people with adequate qualifications and experience in the technical areas covered by the relevant syllabus. Although there is an expectation that tutors will hold a relevant qualification of a level at or above that which is being taught, tutors who are able to demonstrate suitable competence or who have specialist subject expertise would be approved as part of a teaching team.

For NEBOSH Certificate and Diploma qualifications a tutorial team will comprise a course leader/lead tutor who is likely to be a Member of an appropriate professional body such as the Institution of Occupational Safety and Health (CFIOSH, CMIOSH, Grad IOSH or equivalent), Institution of Fire Engineers (FIFireE, MIFireE, AIFireE), Institute of Environmental Management and Assessment (IEMA), The Chartered Institution of Water and Environmental Management (CIWEM) or other relevant body.

For the NEBOSH Health and Safety at Work Qualification(s) a course leader/lead tutor will likely hold the NEBOSH National General Certificate or similar.

In accrediting programmes, NEBOSH considers the balance of expertise within tutorial teams; accreditation does not imply that any tutor is individually approved or accredited by NEBOSH.
Course


So, it appears that NEBOSH will accept GradIOSH , but yiu need to contact NEBOSH directly for confirmation as there are likely to be a range of factors they will consider.