Electroplating and pickling shops: emissions, workplace air, extraction and operating permit

When is an electroplating shop a listed source?

Under Annex No. 2 to Act No. 201/2012 Coll., on Air Protection, electroplating and pickling fall under code 4.12 – Surface treatment of metals, plastics or other non-metallic objects.

Decree No. 415/2012 Coll. expressly includes here, in particular, pickling, electroplating, phosphating (phosphatising) and polishing using electrolytic or chemical processes.

The decisive factor for classification is the total designed capacity of the process bath volume, excluding rinsing baths.

Rinsing tanks are not counted towards the capacity under code 4.12. For a process line, it is therefore advisable to prepare a list of all tanks stating their volume and purpose.

Operating permit for an electroplating shop

An electroplating shop classified under code 4.12 must hold an operating permit issued by the regional authority.

The permit specifies, in particular, the classification of the source, the permitted capacity, emission limits, the method of determining emissions, stacks and the technical operating conditions.

When preparing a new electroplating line or a significant change to an existing shop, an expert report by an authorised person is usually also prepared. A dispersion study is not automatically required for code 4.12 alone, as designated in Annex No. 2 to the Act. However, a specific plant may include other sources for which this obligation arises.

Indicative prices for the application and related documentation are given in the article How much do an expert report, dispersion study, operating rules and operating permit cost.

Which emission limits apply up to 30 m³

For surface treatment with a total designed process bath capacity of 1 to 30 m³ inclusive, Annex No. 8 to Decree No. 415/2012 Coll. sets the following selected emission limits.

The stated limits apply under the conditions defined by the Decree. For baths, the volume of the individual bath is also important – some limits apply to baths with an individual designed volume of 1 m³ or more.

In a specific assessment, it is therefore not enough to know the sum of the volumes of the whole line. The volume and chemical composition of the individual process tanks must also be known.

Electroplating shops with a bath volume above 30 m³

For plants with a total designed process bath volume greater than 30 m³, the Decree sets separate emission limits according to the chemicals used.

For an electroplating shop of this size, code 4.12 is also marked in column C of Annex No. 2 to the Act. Operating rules are therefore a mandatory part of the operating permit.

Which baths are decisive for emissions

The intensity of emissions is not directly proportional to the tank volume alone. The chemical composition, the concentration of the bath, its temperature, the movement of products, the electrochemical process and the intensity of gas evolution are all highly significant.

From the perspective of air protection and the work environment, the following are often significant, for example:

• pickling baths with hydrochloric, sulphuric, nitric or hydrofluoric acid,
• chromium plating, nickel plating and other electroplating baths containing hazardous metal compounds,
• processes with evolution of hydrogen, aerosols or acid vapours, and operations involving topping up, cleaning and draining baths.

For an initial assessment, we therefore need a list of all process baths, their volumes, operating temperatures and the chemicals used. Without these data, the scope of emission requirements or measurement cannot be reliably determined.

Extraction above electroplating tanks

Local exhaust ventilation at an electroplating shop has two functions. It limits the concentration of chemicals in the breathing zone of workers and, at the same time, conveys the emissions in a controlled manner to the abatement equipment and subsequently into the outdoor air.

In practice, for example, lateral slot extraction, extraction from one or more sides of the tank, or enclosure of the process area is used. The resulting efficiency depends on the tank width, the volume of extracted air, the bath temperature, the movement of the racks and the layout of the line.

Insufficient extraction capacity may cause vapours and aerosols to escape into the hall. Excessive extraction, conversely, increases the energy demand of the operation, heat consumption and the load on the air scrubber.

Extraction should therefore be designed for the specific tank and technological process.

Wet scrubber and monitoring of its operation

Waste air from pickling and electroplating baths is usually routed to a wet scrubber or other absorption equipment. Efficiency depends on the type of pollutant, the scrubbing medium used, its pH, circulation and the design of the equipment.

From 2026, greater emphasis is also placed, for selected more significant sources, on continuous monitoring of the operating parameters of emission abatement equipment.

For code 4.12 with a bath volume above 30 m³, this requirement is among the relevant provisions of the Decree. For absorption – a wet scrubber – the parameter monitored may, depending on the type of captured substance, be for example the scrubbing medium inflow, the liquid level or another parameter specified in the operating permit.

The purpose is to demonstrate that the emission abatement equipment was actually functional during operation of the electroplating line.

How often emissions are measured

The frequency of one-off measurement depends on the source category and the specific conditions of the permit.

For sources under point 3.8.1, i.e. surface treatment with a bath volume of 1 to 30 m³ inclusive, the Decree provides as standard for one-off emission measurement once every 3 calendar years.

For sources with a bath volume above 30 m³, a generally stricter regime applies and periodic measurement may be required once per calendar year. If the emission level is ensured by abatement technology and the permit prescribes continuous monitoring of the relevant operating parameter, a three-year frequency may apply under the conditions of the Decree.

The first measurement is carried out no later than 4 months after the source is first put into operation. The same deadline applies after a change of raw material or an intervention in the technology that may lead to a change in emissions.

The current operating permit is always decisive.

Emissions to air and workplace air are two different assessments

The stack of an electroplating shop is assessed under the Air Protection Act. Employee exposure is assessed under Government Decree No. 361/2007 Coll..

An emission concentration measured in the stack therefore cannot be used as evidence that employees are not exposed to excessive exposure.

In the work environment, samples are taken in the employee's breathing zone and the results are compared with the PEL – permissible exposure limits and the NPK-P – highest permissible concentrations.

Very low limits apply to some substances common in electroplating shops.

For nickel, cyanides, metal aerosols and other substances, the limit depends on the specific chemical form. The scope of measurement is therefore determined according to the composition of the baths and the safety data sheets, not merely by the name of the process, such as "nickel plating" or "chromium plating".

When workplace air measurement is needed

Measurement of chemical substances is usually needed for job categorisation, upon a change of technology or of the chemical composition of the baths, and at the request of the regional public health authority.

At an electroplating shop, it is advisable to distinguish the individual work operations. An employee may be exposed only minimally during routine operation of an automatic line, but significantly higher exposure may arise during manual hanging of products, cleaning a tank, topping up concentrate or dealing with a malfunction.

For job categorisation under Decree No. 432/2003 Coll., the concentrations actually measured in the employee's breathing zone are assessed.

For common chemical substances, a job is classified into the second category as soon as the average full-shift concentration exceeds 30 % of the PEL value, even if the PEL itself has not yet been exceeded. Special rules apply to carcinogenic, mutagenic and other highly hazardous substances.

Chromium VI, nickel and other hazardous substances

Some electroplating processes require increased attention because of the properties of the chemicals used.

Hexavalent chromium compounds have a very low exposure limit and some are classified as carcinogenic. For nickel plating processes, the assessment depends on the chemical form of the nickel and the nature of the aerosol.

When designing the measurement, we therefore recommend working with the current safety data sheets of all products used and with the chemical composition of the process baths.

This makes it possible to determine whether, for example, HCl, HNO₃, H₂SO₄, chromium, nickel, cyanides, fluorides or other substances should be measured.

Operating rules for an electroplating shop

For an electroplating shop with a total designed process bath volume above 30 m³, operating rules are mandatory.

The document should describe the process baths, extraction, emission abatement equipment, stacks, the operating parameters of scrubbers, inspections, maintenance and procedures for malfunction conditions.

At an electroplating shop, the link between a specific group of tanks, the extraction branch and the stack is particularly important. The operating rules must make clear where emissions from pickling, nickel plating, chromium plating or other processes are discharged and through which emission abatement equipment.

The same designation of sources and stacks should also be used in the operating permit, in emission measurement reports and in the summary operating records in ISPOP.

When to address a change of the operating permit

Electroplating lines are often modified during operation. A new tank is added, the chemical composition of a bath changes, capacity is increased or the ventilation is reconstructed.

We recommend reviewing the need for a permit change in particular in the event of:

• installation or enlargement of process tanks and a change in the total designed volume,
• use of a new acid, metal or other chemical with different emissions,
• a change to the extraction, air scrubber, stack or operating mode of the line.

Exceeding the 30 m³ threshold is especially significant, because the scope of emission requirements changes and the obligation to have operating rules arises.

What to prepare before permitting or measurement

For the assessment of an electroplating shop, it is advisable to create a simple overview of the whole line.

This overview can subsequently be used for the expert report, the operating permit application, the operating rules and the preparation of measurement.

What you can send us and what we will verify

For an initial assessment, you can send us:

• a list of process and rinsing tanks with their volume, operating temperature and the chemicals used,
• safety data sheets, an extraction diagram, parameters of wet scrubbers and stacks, and photographs of the electroplating line,
• the valid operating permit, operating rules, emission measurement reports, workplace air measurement results or a KHS requirement.

We will verify the classification of the electroplating shop, the total designed bath volume, emission limits, the scope of measurement and the obligation to have operating rules. At the same time, we can assess workplace air and propose measurement of chemical substances according to the specific composition of the baths used.

You will find more information on the page Operating permit – NATURCHEM.

Related legislation

Act No. 201/2012 Coll., on Air Protection

Decree No. 415/2012 Coll., on the Permissible Level of Pollution and Its Determination

Government Decree No. 361/2007 Coll., laying down conditions for the protection of health at work

Decree No. 432/2003 Coll., on the conditions for classifying work into categories