OHS Prequalification When Selecting Contractors

Why is contractor OHS prequalification done at the tender stage?

A metalworking factory obtains three quotes for the annual maintenance of its overhead cranes and agrees with the firm offering the lowest price. When the firm arrives on site, half the team has no working at height training and the periodic inspection report for the platform they have brought cannot be found. Work stops, the schedule slips and arguments begin. A contractor OHS prequalification assessment is the way to see this problem before the contract is signed, at the lowest cost.

The legislation gives important duties to a business working with contractors:

• Art. 23 of Law No. 6331 on Occupational Health and Safety: employers sharing the same work area cooperate in implementing OHS measures, coordinate their activities to prevent risks and inform each other.
• Art. 15 of the Risk Assessment Regulation: the subcontractor carries out a risk assessment for its own work and gives a copy to the principal employer; the principal employer integrates it with its own assessment and monitors it.
• Art. 22 of the 2026 training regulation: the principal employer checks the training certificates of subcontractor workers and provides information on workplace-specific risks before work starts.

We explained how responsibility is shared in our article on OHS when working with subcontractors, and the documents to request at the start of work in our article on the OHS documents to request from subcontractors. This article focuses on one step earlier: the stage of selecting the firm.

The contractor evaluation form: six sections

The prequalification form is sent to the contractor with the invitation to tender and consists of questions requiring evidence. The weightings are adjusted to the risk level of the work; the distribution below is an example.

Score each question from 0 to 3: 0 no evidence, 1 a declaration but weak evidence, 2 evidence provided, 3 strong evidence and practice can be demonstrated. Set a threshold for the total, for example 70 per cent. Some questions, however, are knock-out questions regardless of the score:

• If the firm has no approved specialist and physician appointment in ISG-KATIP for its own workers,
• If it proposes working with staff who lack the vocational training or operator certificate the job requires,
• If the lifting or pressure equipment it will bring has no valid periodic inspection report,

the firm is not invited to tender, whatever its total score. For equipment inspection intervals see our article on periodic inspection intervals for work equipment, and for occupations requiring a certificate see our article on the vocational training certificate requirement.

How do you read a contractor's OHS record?

From a safety point of view, subcontractor selection can be most misleading in this section. Points to watch:

• Read numbers as rates. One accident at a ten-person firm and one accident at a two-hundred-person firm are not the same thing. If possible, ask for the accident frequency rate, i.e. the number of accidents per million hours worked. For the calculation method, see our article on OHS performance indicators.
• Treat a "zero accidents" claim with caution. A firm that keeps near miss records and also reports minor incidents is usually more reliable than a firm that provides no records at all.
• Ask what was learned from serious incidents. See the root cause report and the measures taken by a firm that has had a fatal or serious accident. A firm that learns may carry less risk than one that has never been questioned.
• Do not ask for personal data. You do not need workers' names and health information in accident records; numbers, incident types and measures are sufficient.
• Make room for new and small firms. Do not automatically eliminate a firm with no record; start with a small, low-risk job and evaluate it under close supervision.

Verification on site: from documents to practice

The score on the form is a decision made at a desk. For high-risk work, add the following verifications:

1. Pre-tender interview: Talk to the firm's team leader who will come to the site. Ask them to describe in their own words the working method and how they will manage the biggest risk.
2. Site visit: If possible, see another job the firm is carrying out in person.
3. Pre-start meeting: After the contract and before work starts, discuss the work plan, permits to work and emergency arrangements with your own specialist, the contractor's OHS lead and the team leader.
4. First-week observation: Observe frequently on site in the first days; record any gap between what was declared on the form and what happens on site.
5. End-of-job evaluation: When the work is finished, score the contractor again under the same headings and enter the result in your approved contractor list.

The OHS specification: what should you put in writing for the contractor in advance?

The OHS specification is given to the contractor as an annex to the tender documents; this way the firm includes the cost of the OHS requirements in its price from the outset. The specification should include:

• Site rules, entry and identity checks, workplace-specific information
• The obligation to comply with the permit to work system; for details see what a permit to work system is
• Energy isolation in maintenance work; see LOTO lockout and tagout
• A hot work permit for welding and cutting
• A minimum PPE list and that PPE will be provided by the contractor
• Documents required for equipment and chemicals to be brought onto the site
• Waste management and daily cleaning of the work area
• The reporting route for accidents, near misses and dangerous situations
• The principal employer's authority to inspect and to stop work in the event of non-conformity

Contract OHS clauses: sample headings

Contract OHS clauses make the specification binding. Sample headings:

1. That the contractor will comply with OHS legislation and the specification
2. That the staff list, training, health and vocational certificates will be submitted before work starts, and that no one not on the list will be admitted to the site
3. That the risk assessment will be submitted before work starts and updated when the work changes
4. That the use of sub-subcontractors is subject to the principal employer's written approval
5. That permit to work and energy isolation rules will be followed
6. That accidents and near misses will be reported to the principal employer on the same day
7. That the principal employer may inspect at any time and stop work when it sees a danger to life, and that this time gives the contractor no right to extra time or payment
8. The contractual sanctions to be applied for non-conformities, and termination of the contract if they recur
9. That periodic inspection reports for equipment will be kept on site with the equipment
10. That the area will be handed back safe and clean at the end of the work

Typical contractor jobs in metal and machinery businesses

In metal and machinery businesses in Bursa and the surrounding provinces, the jobs most often contracted out, and the points to look at particularly in prequalification, are:

• Overhead crane and lifting equipment maintenance: Working at height training, energy isolation, the inspection report for their own platform.
• Machine moving and installation: Lifting plan, inspection of slings and chains; see slings, chains and lifting accessories.
• Roof repairs and installation work on roofs: Fall risk. Under Annex 1 of the Regulation on Workplace Buildings and Annexes, access to roofs that are not sufficiently strong is not permitted without equipment ensuring safe working.
• Welding and cutting: Hot work permit, fire watch, removal of flammables.
• Electrical panel and installation work: Competent staff and energy isolation; see electrical panel safety.
• Compressor and pressure vessel maintenance: Depressurisation and test procedure.

In our OHS specialist service, we prepare the prequalification form according to the risk level of the work, evaluate the evidence received and propose drafts for the specification and the contract OHS clauses. Other risks in the sector are on our metal and machinery page.

Frequently Asked Questions

Is a contractor prequalification form a legal requirement?

There is no requirement in the legislation under the name "prequalification form". However, the principal employer must coordinate with the contractor, integrate the risk assessment with its own and check training certificates. Prequalification is the practical way to fulfil these duties before work starts.

Can we work with a contractor that offers the lowest price but has a low score?

Do not work with a firm that fails the knock-out questions. If you have to work with a firm that falls slightly below the threshold, tie the gaps to a written improvement plan, limit the work to low-risk parts and increase supervision on site.

Can a contractor bring its own sub-subcontractor?

Make this subject to the principal employer's written approval in the contract. Before giving approval, evaluate the sub-subcontractor with the same prequalification form; a firm you do not know working on site disrupts coordination.

Is prequalification needed for short jobs too?

Yes, but it can be scaled down. For a low-risk job lasting a few hours, a short checklist may be enough; for jobs requiring working at height, hot work or energy isolation, however short, the knock-out questions should be applied.