In brief
The certificate of the specialist assigned to your workplace must match your hazard class; A for very hazardous, at least B for hazardous and at least C for less hazardous. Certificates are registered digitally in ISG-KATİP and are renewed every five years; a certificate that is not renewed is suspended. An assignment made with a certificate of the wrong class or a suspended certificate may be treated in an inspection as if no assignment had been made.
Why should you check the certificate yourself?
A person to be assigned as an OHS specialist or workplace physician must hold a valid certificate under the relevant regulation (Regulation on OHS Specialists Art. 7/1; Regulation on Workplace Physicians and Other Health Personnel Art. 7/1). Obtaining the service from an OSGB (joint health and safety unit) does not take this obligation away from you: under Art. 4 of Law No. 6331, outsourcing the service does not remove the employer's responsibilities.
That is why checking an OHS specialist's certificate is not a task to be done once when the contract is signed and then forgotten. It should be repeated when the specialist changes, when your hazard class changes and when the certificate's renewal date approaches. For how to check the assignment record itself in ISG-KATİP (the Ministry's online OHS registration system), see our article on checking assignments in ISG-KATİP; this article focuses on the person's certificate.
Classes A, B and C and matching the hazard class
The Law links the specialist's certificate class to the workplace's hazard class (Art. 8/5). The Regulation on OHS Specialists also states that holders of a class C certificate may work in less hazardous workplaces, holders of a class B certificate in less hazardous and hazardous workplaces, and holders of a class A certificate in workplaces of all hazard classes (Art. 7/2).
| Workplace hazard class | Specialist certificate accepted | Not accepted |
|---|---|---|
| Less hazardous | A, B or C | — |
| Hazardous | A or B | C |
| Very hazardous | A only | B, C |
The answer to finding an OHS specialist's class is written on the specialist's certificate; but knowing how classes are upgraded makes it easier to question the information you are given. Under the Regulation, a person who documents by contract that they have actually worked for at least three years with a class C certificate and who attends class B training and passes the exam receives a class B certificate; a person who has actually worked for at least four years with class B and passes the class A exam receives a class A certificate (Art. 8/1). Those who score at least 70 out of 100 in the exams pass (Art. 28/4). A claim such as "got the certificate last month, class A" should therefore be treated with suspicion on its own.
If you are not sure of your hazard class, verify it first; you can check your class according to the NACE code of your main activity with our article on how to find your hazard class.
Checking an OHS specialist's certificate: step by step
The Regulation on OHS Specialists states that, after certificates are moved to the e-Government system, certificates for eligible candidates will be issued electronically by the Directorate General (Art. 28/A). According to the Ministry's ISG-KATİP guide, the certificate is registered digitally through ISG-KATİP after payment and approval. As an employer, proceed with these steps:
- Confirm your own hazard class. Checking is meaningless if you do not know which class of certificate you are looking for.
- Ask the OSGB for written information. The name of the specialist to be assigned, the certificate class, the certificate number and the renewal date should be written in the quotation or in an annex to the contract.
- See the specialist's own record. The specialist can view their certificate from their own account in ISG-KATİP. Ask for a printout or screenshot of the certificate record and add it to your contract file.
- Compare on the approval screen. Before approving a pending assignment in ISG-KATİP, compare the assigned person's name and certificate class with the information the OSGB gave you in writing. For the contract approval steps, see our article on ISG-KATİP contract approval.
- Follow suspension and cancellation notices. Those whose certificates have been suspended and those whose certificates have been cancelled are announced on the Directorate General's website (Art. 32/4).
- Keep the record up to date. Write the date and result of the check in your OHS file; repeat the same steps when the specialist changes.
Checking certificates in ISG-KATİP and specialist certificate validity
The certificate's validity matters as much as its class. The Regulation on OHS Specialists requires the certificates of persons and organisations authorised under the regulation to be renewed every five years (Art. 20/1). The certificates of persons who do not apply before the renewal date are suspended until the renewal process is completed; those who apply must complete the process within 60 days of the renewal date (Art. 20/7). The renewal application is also made through ISG-KATİP.
Renewal is not the only reason for suspension. The certificates of certified persons are suspended for six months when their total warning points reach 100 (Art. 34/1). The certificate of a specialist whose negligence in a workplace accident or occupational disease resulting in a worker's death or disability has been established by a final court judgment is also suspended for six months, and all of that specialist's contracts in ISG-KATİP are cancelled automatically (Art. 34/2). During the suspension, the person cannot exercise the powers based on their certificate (Art. 34/3).
Four mismatches commonly found in practice
When checking certificates, the problem is usually not a forged certificate but information that does not match. Stop before approving in these four situations:
- The name in the quotation differs from the name on the approval screen. If someone other than the class A specialist named in the quotation appears in ISG-KATİP, ask in writing for the new person's certificate class and renewal date; do not approve until you receive an explanation.
- Your hazard class has gone up. For example, if laser cutting of metals has become one of your main activities, your class rises to very hazardous; the current class B specialist is no longer sufficient.
- The renewal date is approaching or has passed. Write the specialist's renewal date in your contract file and, as the date approaches, ask whether the renewal application has been made.
- More than one specialist is assigned. In shift-based workplaces, assignment is made to suit the shifts; however, the calculated working time cannot be split between more than one specialist outside the shift pattern (OHS Specialists Reg. Art. 7/4). Check the certificate of each assigned specialist separately.
Checking a workplace physician's certificate
Workplace physicians do not have classes A, B and C as specialists do; the physician must hold a workplace physician certificate issued under the Regulation on Workplace Physicians and Other Health Personnel (Art. 7/1, 8). The certificate is issued to physicians who complete the workplace physician training programme and pass the exam, and to those who meet the other conditions listed in the regulation. Follow the same route for checking a workplace physician's certificate: ask the OSGB in writing for the physician's name and certificate details, see the physician's certificate record in ISG-KATİP and compare it with the information on the approval screen.
Physicians' certificates are also renewed every five years, and the certificate is suspended if no renewal application is made (Physicians and DSP Reg. Art. 27/1, 27/7). A certificate issued by the Ministry is also required for other health personnel (DSP); DSP are assigned in very hazardous workplaces with 10 or more workers. For the physician's duties, see our article on workplace physician duties.
The consequences of a class mismatch and a suspended certificate
Assigning a class C specialist to a workplace in the hazardous class, or a specialist with a suspended certificate continuing in the role, means that an assignment meeting the qualifications required by the Law has not been made. In an inspection, this may be treated as failure to fulfil the obligation to assign a specialist. The 2026 base fine for breaching this obligation is TL 111,263 per person not assigned, and the same amount is applied for every month the breach continues. The amount is increased according to the size and hazard class of the workplace: for example, in a hazardous workplace with 10–49 workers it reaches TL 166,894.50 per person with a 50% increase. For your own situation, you can use our OHS administrative fines tool.
The most common cause of a mismatch is a change in the workplace's hazard class. A change in the main activity is notified within one month; if the class changes, obligations such as the specialist class, the monthly time and, where necessary, the assignment of DSP are fulfilled according to the new class within 90 days. When your class goes up, ask your OSGB in writing for the name and certificate details of a specialist suitable for the new class.
Bursa Sistemer is a Ministry-authorised OSGB providing OHS specialist services in Bursa and neighbouring provinces. Whichever OSGB you work with, we recommend asking in writing for the specialist's name, certificate class and renewal date at the quotation and contract stage. For other questions to ask when choosing an OSGB, see our article on what to look for when choosing an OSGB.
Frequently Asked Questions
How do I find out an OHS specialist's class?
Ask the OSGB in writing for the specialist's name, certificate class and certificate number; get a printout of the certificate record in ISG-KATİP from the specialist and compare it with the information on the ISG-KATİP approval screen.
Can a class C specialist be assigned to a workplace in the hazardous class?
No. In the hazardous class at least a class B specialist, and in the very hazardous class only a class A certified specialist, can be assigned. A class C certificate is only valid for less hazardous workplaces.
Does a specialist's certificate have a validity period?
Certificates are renewed every five years. If no application is made before the renewal date, the certificate is suspended until the renewal process is completed; it can also be suspended for six months for reasons such as warning points or a court judgment.
Do workplace physicians also have a class?
No. There is no A, B, C classification for workplace physicians; it is enough for the physician to hold a valid workplace physician certificate with an up-to-date renewal.
A certified specialist matched to your hazard class: site inspections, approved logbook, training plan, annual plan and report follow-up.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.