Start by finding the KHS opinion
Before you start ordering individual measurements, take out the opinion of the regional public health authority (KHS) on the project and go through the conditions that were set when it was being permitted.
This is usually the best starting point.
Under Act No. 258/2000 Coll., on Public Health Protection, the public health protection authority is an affected administrative authority and may impose the conditions necessary to protect public health.
In practice, it may be stipulated, for example, that before the building is used, a measurement of lighting, noise from outdoor technology or another factor must be submitted.
In practice: Do not automatically order a "complete hygiene measurement of the hall". First find out what is actually required and which other factors result from the operation.
With a new production hall, two different situations may arise. Some parameters can be verified before production starts. Others can be measured meaningfully only once the machines are running, extraction is in operation and employees are performing their normal work.
What is most often addressed at a new facility
The scope depends mainly on what will actually be done in the building.
Lighting is usually addressed after the lighting system has been completed and the workstations have been laid out.
Noise at the workplace must be assessed for machines, presses, CNC machines, compressors, machining or production lines. The measurement must take place under representative operation.
Noise in the surroundings concerns above all ventilation, cooling, compressors, vents, loading ramps and outdoor technology. A noise study may already be needed at the design stage, followed by a control measurement after completion.
Microclimate conditions are important especially in operations with heat stress, air-conditioned halls or workplaces with significant process heat.
Dust and chemical substances are addressed, for example, in grinding, welding, woodworking, painting, bonding, degreasing or work with powder raw materials.
Vibration may be significant when working with hand-held vibrating tools or some machines.
Not every hall therefore needs all of the measurements listed. An administrative warehouse with a few employees will have completely different requirements from a paint shop, a welding shop or a multi-shift production operation.
Lighting: one of the most common conditions
With lighting, the situation is more specific than with most other factors.
Government Decree No. 361/2007 Coll. sets requirements for the lighting of workplaces and for verifying the actual lighting conditions.
In the design phase, lighting is designed and verified by calculation. After completion, what matters is whether the luminaires actually installed, their output and their layout correspond to the design.
If the type, number, output or layout of the luminaires changes during construction, the original lighting calculation may no longer correspond to the actual state.
Before the measurement, the final luminaires should therefore be installed, and it should be clear where the actual workstations will be and what activity will be performed at them.
For example, it is not enough to measure the average lighting of the whole hall if there are workplaces inside with different visual demands.
Daylight is a separate question
Electric lighting and daylight are not the same thing.
Government Decree No. 361/2007 Coll. also sets requirements for daylight in indoor workplaces with permanent work.
If the project works with daylight or a combination of daylight and electric lighting, it is advisable to verify what was actually designed in the project and what the KHS opinion required.
This is often important, for example, in large production halls where the workstations are at different distances from windows and rooflights.
Noise at the workplace: there is no point in measuring an empty hall
A very common mistake arises when the investor wants to measure the noise of the production hall before occupancy approval even though the technology is not yet in normal operation.
Such a measurement may say nothing about the actual exposure of employees.
For normal steady and varying noise at work, Government Decree No. 272/2011 Coll. sets a permissible exposure limit of LAeq,8h = 85 dB.
The value of 85 dB is not, however, a universal limit for every workplace. For some work that demands attention, concentration or communication, stricter requirements apply.
When measuring a production hall, it is therefore necessary to know the actual work activity, the duration of exposure, the worker's movement and the operation of the individual machines.
If an employee, for example, operates a noisy line for part of a shift and works away from it for the rest of the shift, the assessment of their exposure must reflect this.
Noise from technology into the surroundings is a different matter
The noise to which an employee is exposed at work and the noise from a facility propagating to neighbouring houses are two different things.
In a new hall, the problems are mainly outdoor or rooftop technology: ventilation, fans, coolers, compressors, heat pumps, extraction or process vents.
Handling on outdoor areas, loading ramps and heavy goods traffic can also be significant.
Ideally, this problem is solved already during design by means of a noise study. After completion, the KHS opinion may require a control measurement of actual operation.
Night operation is particularly important. Equipment that complies without problems during the day may be the decisive noise source at night.
Ventilation: it is not enough that the design says "VZT"
Workplaces must be provided with sufficient air exchange.
Government Decree No. 361/2007 Coll. sets the minimum amount of fresh outdoor air supplied according to the physical demands of the work and the presence of pollutants.
For a production hall, it is therefore not enough to state that the building has air-conditioning and ventilation (VZT).
It is necessary to know, in particular, the supply and exhaust air volumes, the VZT capacity, the method of control and the function of local extraction at individual technologies.
Local extraction is of particular importance at sources of dust and chemical substances. Pollutants should, as far as technically possible, be captured as close as possible to where they arise.
If the technology or the number of employees changes during construction, it is advisable to verify whether the originally designed VZT still corresponds to the actual operation.
Measure dust and chemical substances only during actual production
For workplace air, the scope of measurement cannot be determined merely from the name of the facility.
In a paint shop, different substances will be decisive than in a welding shop, woodworking or bonding.
It is therefore first necessary to know the technology and the products used.
Safety data sheets are a very important input. Their composition determines which chemical substances should be assessed in workplace air.
In welding, for example, it is necessary to know the welded material and the filler materials. Determining total dust alone may not be enough. Depending on the technology, specific metals or other components of the welding aerosol may be significant.
In woodworking, it is necessary to distinguish the type of wood dust and the nature of the work operations.
In painting, bonding and degreasing, the specific organic substances contained in the products are important.
The measurement must take place under representative conditions. If the line runs at only a fraction of its normal output during the measurement, or a product is used that does not correspond to normal production, the result may not reflect the actual exposure of workers.
What can be measured before production starts and what only afterwards
Lighting can usually be verified after the building has been completed and the final lighting system installed.
The function and parameters of the VZT can be checked once it has been completed and adjusted.
Noise from outdoor process equipment can be measured after it has been started up, provided a representative operating mode can be created.
By contrast, workplace noise, dust and chemical substances usually require actual operation of the technology.
For more complex production, a trial operation may therefore be a suitable solution. During it, the technology can be adjusted and the working conditions documented objectively in a situation that corresponds to the future normal operation.
Occupancy approval and job categorisation are not the same
It is advisable to distinguish between the requirements associated with putting a building into use and the subsequent categorisation of the employer's work.
Under Section 37 of Act No. 258/2000 Coll., work is classified into four categories according to the extent to which working-condition factors occur.
The results of measurements of noise, dust, chemical substances, vibration or other factors may later serve as a basis for categorisation.
It is therefore advantageous to plan the measurements needed to put the facility into use together with the subsequent assessment of working conditions.
A correctly performed measurement may be usable for several purposes, and there is no need to measure the same factor repeatedly without reason.
The most common problem: reality no longer matches the design
With new facilities, it very often happens that changes occur during construction.
The design assumed different luminaires. The technology was relocated. A compressor was added. The VZT has a different output. Production will run in two shifts instead of one. Night dispatch was added. The number of workers increased or the chemicals used changed.
Each of these changes may affect the original hygiene assessment.
Before the final measurement, it is therefore important not to work only with the original design but to compare it with the actual execution.
Checking the operating regime is just as important. If, for example, the noise study assumed daytime operation only and the investor ultimately decides to run the technology at night as well, the original conclusion may no longer be usable.
What to prepare before ordering the measurement
For a quick assessment, we usually need only:
- the KHS opinion,
- the current floor plan of the hall or facility,
- a brief description of the technology,
- a list of job positions,
- operating hours and the number of shifts,
- the lighting design,
- the VZT design,
- safety data sheets of the chemical products used,
- a list of significant machines,
- any noise study.
From these documents, it is usually possible to determine fairly quickly what has to be submitted before the building is used and what makes sense to measure only during trial or normal operation.
Typical mistakes that may needlessly delay putting the operation into use
The most common problem is not the measurement itself but its poor timing.
The noise of a production line that is not yet complete is ordered. Workplace air is measured at minimal production. Lighting is measured before the final workstations are installed. Safety data sheets are only looked for when the laboratory arrives.
Another problem is the automatic ordering of all possible factors without first checking the documentation.
The company may then pay for measurements that nobody needed while lacking a document that the KHS opinion actually required.
The most efficient approach is therefore to first check the conditions set by the KHS and the actual state of the operation, and only then draw up the measurement plan.
How to proceed before the planned occupancy approval
Ideally, the hygiene documentation should be dealt with well in advance, not a few days before the planned putting of the operation into use.
First, the KHS opinion and the design are reviewed. Then the actual execution of the technology, lighting and VZT is checked.
Next, the measurements are divided into those that can be carried out before production starts and those that require representative operation.
This helps avoid a situation in which, at the last minute, it turns out that, for example, the lighting is unsatisfactory, a noise-protection measure is missing or the extraction of the technology is insufficient.
What you can send us for assessment
If you are preparing a new production hall or facility, send us the KHS opinion, the current floor plan, a brief description of the technology, a list of job positions, the lighting and VZT design and the safety data sheets of the chemical products used.
From these documents, we will check which measurements are actually needed before the operation is put into use, which can be carried out immediately and which it is advisable to postpone to trial or normal operation.
At the same time, the measurements can be designed so that their results are, where possible, also usable for the subsequent assessment of working conditions and job categorisation.
You will find more information on the page NATURCHEM work environment measurement.
Brief summary
Before occupancy approval of a production hall or facility, there is no universal package of measurements.
First, it is necessary to check the KHS opinion and the actual execution of the building. Lighting can usually be dealt with once the workplace is completed, whereas noise from production technology, dust or chemical substances require representative operation.
The most important thing is correct timing. A well-planned measurement can at the same time meet the requirement for putting the facility into use and provide a good basis for the subsequent assessment of working conditions.
Factual basis of the article
The basic regulation is Act No. 258/2000 Coll., on Public Health Protection, in particular the provisions on job categorisation and on the competence of public health protection authorities.
Requirements for the work environment, ventilation, microclimate conditions, chemical substances, dust, workplace premises and lighting are set by Government Decree No. 361/2007 Coll..
Hygiene limits for noise and vibration and the rules for their assessment are laid down by Government Decree No. 272/2011 Coll..
The criteria for classifying work into categories are set by Decree No. 432/2003 Coll..
General requirements for buildings are also laid down by Decree No. 146/2024 Coll., on Construction Requirements.