In brief
The hazard class is determined by the 6-digit NACE code of the main activity carried out at your workplace; the list was completely renewed on 13 March 2025 with NACE Rev.2.1. Take your code from the SGK workplace registration and compare it with the current list; if your class changes, complete the new obligations within 90 days.
Why is the hazard class the starting point for everything?
"Which class is my company in?" is the first question in occupational health and safety planning. In Turkey, every workplace falls into one of three hazard classes: less hazardous, hazardous and very hazardous. To find your hazard class, you need to know your workplace's NACE code and find that code in the Ministry's current list; but you should also check that the code actually describes the work you do.
The class sets the level of almost every obligation: how many minutes per month the workplace physician and OHS specialist will work, which class of certificate the specialist must hold, whether other health personnel (DSP) are required, training hours, the periodic examination interval and the renewal period of the risk assessment. The surcharge rates on administrative fines also vary by class.
In an industrial city like Bursa, where automotive supply, textiles, metal, furniture and food operate side by side, two neighbouring factories in the same OIZ (organised industrial zone) may be in different classes. So do not rely on what a neighbouring company or an old table on the internet says; look at your own registration and the current list.
The main activity rule: what determines the class?
Under Art. 2 of the Communiqué on Workplace Hazard Classes Relating to Occupational Health and Safety, the hazard class is determined by the class of the main activity carried out at the workplace. In practice, this means:
- The main activity is the workplace's reason for existing. In an automotive parts factory, the main activity is parts manufacturing; the canteen, accounting and dispatch are ancillary activities and do not determine the class.
- If in doubt, the founding purpose is considered. If it is not clear which is the main activity, the workplace's founding purpose is taken as the basis.
- If there are several main activities, the higher class applies. In a facility doing both garment making and fabric dyeing, the activity with the higher hazard class determines the class.
- A change in the main activity must be notified. The employer notifies the Ministry of Labour and Social Security of a change in main activity within one month at the latest.
The class is determined per workplace. If the same company has a head office and a factory with separate SGK registrations, each workplace's own main activity is considered. The office may be less hazardous while the factory is hazardous or very hazardous, and the specialist and physician times are calculated separately for each workplace.
What changed in 2025? NACE Rev.2.1 and the 6-digit list
The list annexed to the Communiqué (Annex 1) was completely renewed by the amendment published in the Official Gazette of 13 March 2025. The new list consists of 6-digit codes prepared according to NACE Rev.2.1, the current version of the activity classification. The list was subsequently amended again on 21 May 2025 and 1 April 2026.
This change has three practical consequences for employers:
- Old codes and old tables are not reliable. Tables prepared according to the 2012 list, old quotations or the cover of an old risk assessment may not show your current class.
- The class of some activities has changed. For example, textile bleaching and dyeing (13.30.01) was very hazardous in the 2012 list; it is in the hazardous class in the 2025 list.
- Check your converted code. Your code may have been converted to the new classification; review once that the description of the converted code correctly describes your main activity.
Primary sources: the text of the Communiqué on mevzuat.gov.tr and the amendment of 13.03.2025 renewing Annex 1 (Official Gazette).
Where can you see your NACE code?
The quickest way to find your hazard class is to start from the activity code in your workplace's SGK workplace registration record. Follow this sequence:
- Get the SGK record. Ask your accountant for the 6-digit code in the workplace registration, together with the workplace registration number. Whoever handles your SGK procedures can access this information easily.
- Compare it with the ISG-KATİP record. Specialist and physician contracts run through ISG-KATİP, the Ministry's online OHS registration system; confirm that the hazard class shown in your workplace's record matches the SGK registration.
- Find the code in the current list. Search for the 6-digit code in the current version of Annex 1 and note the class next to it.
- Read the description. Does the code's definition describe your main activity? If you do nickel plating under a code that says "machining", there is a problem.
The activity code on the tax certificate may not always be the same as the one in the SGK record. The Communiqué bases the assessment on the workplace's registration records and the main activity on which the registration is based; if the two codes differ, clarify this with your accountant.
Common mistakes in this check are:
- The code chosen at incorporation never being updated. The company started in trading and moved into production over time, but the record still shows the original activity.
- A new line being overlooked. A plating, painting or laser cutting line has been added to the existing facility; the main activity has changed but no notification has been made.
- Codes getting mixed up in group companies. The records of two companies operating at the same address show each other's activities.
- Relying on an old table. A class taken from the 2012 list may be different in the 2025 list.
If one of these mistakes applies, correcting it early prevents both receiving inadequate service under the wrong class and unnecessary cost.
Verified sample codes (2025 list)
The codes below have been verified against the 2025 Annex 1 and are selected from sectors commonly found in Bursa. Check the full list for your own code.
| Code | Activity | Hazard class |
|---|---|---|
| 29.10.02 | Manufacture of motor cars | Hazardous |
| 29.32.20 | Parts and accessories for motor vehicles (gearboxes, brakes, shock absorbers, etc.) | Hazardous |
| 29.32.21 | Body parts | Hazardous |
| 29.31.04 | Wiring harnesses for vehicles | Hazardous |
| 25.53.01 | Machining and welding work | Hazardous |
| 25.53.03 | Laser cutting of metals | Very hazardous |
| 25.51.01 | Nickel plating of metals | Very hazardous |
| 13.20.16 | Cotton weaving | Hazardous |
| 13.30.01 | Textile bleaching and dyeing | Hazardous (very hazardous in the 2012 list) |
| 14.21.01 | Outerwear (garment making) | Less hazardous |
| 31.00.01 | Manufacture of bedroom, kitchen and similar furniture | Hazardous |
| 10.71.02 | Manufacture of bread | Less hazardous |
| 43.12.00 | Site preparation | Very hazardous |
| 43.22.06 / 43.22.07 | HVAC installation and maintenance | Very hazardous |
| 62.10.00 | Software | Less hazardous |
| 69.20.02 | Accounting | Less hazardous |
| 70.20.01 | Business consultancy | Less hazardous |
The table shows an important point: within the same metal sector, machining and welding are hazardous, while laser cutting and nickel plating are very hazardous. When a workshop starts carrying out one of these activities as its main activity, its class may also change. For sector-specific risks, see our automotive supply industry, metal and machinery and textiles pages.
What changes by class?
| Obligation | Less hazardous | Hazardous | Very hazardous |
|---|---|---|---|
| Workplace physician (per employee per month) | 5 min | 10 min | 15 min |
| OHS specialist (per employee per month) | 10 min | 20 min | 40 min |
| Specialist certificate | At least class C | At least class B | Class A |
| Other health personnel | Not required | Not required | Required with 10 or more employees |
| Basic OHS training | 8 hours | 12 hours | 16 hours |
| Training refresher | Every 3 years | Every 2 years | Every year |
| Periodic examination | At least every 5 years | At least every 3 years | Every year |
| Risk assessment renewal | At least every 6 years | At least every 4 years | At least every 2 years |
| First aider | 1 per 20 employees | 1 per 15 employees | 1 per 10 employees |
By entering your number of employees, you can see what these values mean for your workplace with the OHS obligation calculator. For the detailed calculation of times, see our articles on physician and specialist working times, and for training rules, the 2026 training regulation.
The class also affects fines. Under Art. 26 of Law No. 6331, in workplaces with 50 or more employees, fine amounts are increased by 50% for less hazardous, 100% for hazardous and 200% for very hazardous workplaces. In workplaces with 10–49 employees, the increase is 50% for hazardous and 100% for very hazardous workplaces. This increase does not apply to fines calculated per employee.
If your class is wrong: how to object and the 90-day rule
If you believe the code or the class is wrong, first establish where the problem lies:
- If the code is wrong: If the activity code in the SGK record does not reflect your main activity, the correction is made through the workplace registration record. Start this process with SGK together with your accountant.
- If the code is correct but the class is disputed: Under Art. 3 of the Communiqué, objections to a workplace hazard class are assessed by the Ministry of Labour and Social Security. The assessment is based on the registration records and the main activity on which the registration is based; no on-site inspection is carried out unless deemed necessary.
If the review finds that the main activity carried out at the workplace differs from the registration records, the class may be redetermined. If an objection to the class of an activity code is accepted, the Communiqué itself is amended; this affects all workplaces using the same code.
The main things to do within 90 days in a workplace whose class has risen are: increasing specialist and physician times to the new minutes, replacing the specialist with one holding a higher-class certificate if necessary, assigning DSP in very hazardous workplaces with 10 or more employees, updating the training and examination plan to the new intervals and reviewing the risk assessment. Continuing to receive services according to the registered class until the objection is resolved is the safest course.
Checking together that your code matches your main activity at the start of OHS specialist and workplace physician services puts all subsequent planning on a solid footing.
Frequently Asked Questions
Does the OSGB determine our hazard class?
No. The class is the one corresponding, in the list annexed to the Communiqué, to the main activity in your workplace's registration record. The OSGB or the OHS specialist can check whether the code matches the main activity and warn you of any mismatch, but cannot change the class on their own. Corrections are made through the SGK record or an objection to the Ministry.
We have more than one activity; which class applies?
Of the activities you carry out as your main activity, the one with the higher hazard class applies. Ancillary activities such as the canteen, warehouse organisation or accounting do not determine the class. If it is not clear which is the main activity, the workplace's founding purpose is considered.
Are my documents prepared under the 2012 list invalid?
Documents do not become invalid automatically; however, if your class changed in the 2025 list, your obligations change too. The risk assessment, training plan and examination intervals should be checked against the new class. Updating the plan in a workplace whose class has fallen also avoids unnecessary cost.
Our class has changed; how long do we have to comply?
Under the Communiqué, in a workplace whose hazard class changes, the new obligations are fulfilled within 90 days and notified to the General Directorate of Occupational Health and Safety. During this period, update the specialist and physician times, the specialist's certificate class, and the training and examination plan according to the new class.
Our office and factory belong to the same company; is the class determined separately?
For each workplace with a separate SGK registration, its own main activity is considered. In Bursa, for companies whose head office is in the city centre and whose production is in an OIZ, the office may be less hazardous and the factory hazardous or very hazardous. Specialist and physician times are also calculated separately for each workplace.
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.