Static Electricity in Coating and Ink Operations: How to Prevent Ignition and Material Damage

Photo: Waldemar Brandt / Unsplash

In facilities involved in the production or application of coatings and printing inks, static electricity is often an underestimated risk. When handling solvent-based systems, powder coatings, or fast-flowing liquids, electrostatic charge can accumulate, which, upon sudden discharge, threatens not only worker safety but also the quality of the final products. Ignition of solvent vapors, damage to sensitive electronic components, or contamination of materials with dust particles are just some of the issues that can be prevented with proper technical measures. This article focuses on practical solutions for identifying risk situations and implementing preventive measures in compliance with REACH and CLP requirements.

Why is static electricity dangerous in coating and printing facilities?

Static electricity is generated by friction or separation of materials with different electrical conductivity, which is a common phenomenon in operations involving paints and inks. Typical sources include mixing, pumping, spraying, filtration, or even simply pouring liquids. The problem arises when the accumulated charge suddenly discharges in the form of a spark – this can, in environments with flammable solvent vapors or dust, cause ignition, explosion, or fire. The risk increases with low-conductivity liquids (e.g., hydrocarbon-based solvents) and in dry environments with low air humidity.

In addition to safety risks, static electricity also damages the materials themselves. In paints, it can cause uneven application, pigment clustering, or reduced adhesion to the substrate. In printing operations, it leads to poor print quality, contamination of printing rollers, or clogging of nozzles in inkjet systems. Prevention is therefore not only a matter of safety but also of quality and production efficiency.

Key sources of static electricity and how to identify them

The most common sources of static electricity in operations include handling liquid raw materials: pumping paints through pipelines, mixing in containers, high-pressure spraying, or filtration through synthetic materials. Solid materials also pose risks – for example, transporting powdered pigments via pneumatic conveyance, friction of plastic packaging against metal surfaces, or movement of workers in synthetic clothing. Identifying sources requires a systematic approach: monitor processes where intense friction, rapid movement of liquids, or separation of materials occurs.

A practical tool for detection is measuring electrostatic charge using specialized instruments such as electrostatic voltmeters or spark detectors. These devices help identify critical areas where charge accumulation occurs. It is also important to monitor air humidity – the ideal range for minimizing static electricity is 40–60%. Lower humidity increases the risk of charge formation, while higher humidity can negatively affect the properties of some coating materials.

Photo: Anastasiya Badun / Unsplash

Technical measures for minimizing risks

The basic measure is grounding all metal components of equipment, containers, and pipelines that come into contact with flammable liquids. Grounding systems must be regularly inspected to ensure their functionality. For liquids with low conductivity (e.g., solvents), it is recommended to use special antistatic additives that increase conductivity and enable charge dissipation. These additives are often based on metal salts or organic compounds and are added in concentrations ranging from 0.1 to 1 % by weight.

In operations with high risk, ionization systems that neutralize static charge using a flow of ionized air have proven effective. These systems are installed near critical points, such as nozzle outlets, filtration units, or conveyor belts. It is also important to select suitable materials for equipment and packaging—such as antistatic plastics or metal containers with grounding. In spray booths, it is necessary to ensure adequate extraction of vapors and dust to minimize the concentration of flammable substances in the air.

Organizational measures and staff training

Technical measures must be complemented by clear organizational rules and employee training. Staff should be familiar with the risks of static electricity, principles of safe material handling, and procedures for emergency situations. Regular training should include practical demonstrations of electrostatic charge measurement, proper grounding, and the use of protective equipment. It is also important to establish a system of regular equipment inspections and maintenance, including documentation of implemented measures.

In facilities handling paints and inks, it is essential to adhere to proper storage and handling principles. Flammable liquids should be stored in grounded containers, separated from heat sources and ignition sparks. When transferring, grounded funnels and hoses must be used, even for small quantities. Workers should wear anti-static clothing and footwear to minimize the risk of charge buildup during movement. In the event of flammable vapor release, work must be stopped immediately, and the area must be ventilated.

Photo: Maik Winnecke / Unsplash

Impact of Static Electricity on Coating and Printing Output Quality

Static electricity does not only pose a safety risk but can also significantly affect the quality of final products. In coating and printing operations, unwanted attraction of dust particles, fibers, or other impurities to material surfaces often occurs, leading to defects such as streaks, uneven coverage, or reduced adhesion. For example, in powder coating applications, static charge can cause premature settling of particles before reaching the surface, resulting in an uneven layer and reduced coating durability.

In printing operations, static electricity is particularly evident when working with thin films or paper, where it can cause layer sticking, improper material feeding, or even damage to print heads. For solvent-based inks, static discharge can lead to premature drying or unwanted chemical reactions that alter color properties. To minimize these issues, it is crucial to maintain optimal air humidity (ideally 40–60%) and use antistatic additives directly in coatings or inks.

Practical Methods for Measuring and Monitoring Static Electricity

Regular measurement of static charge levels is essential for risk prevention and ensuring production quality. Specialized instruments such as electrostatic voltmeters or field meters are used for this purpose, allowing detection and quantification of charge on material surfaces, equipment, or in the air. Measurements should be conducted at critical points, such as conveyor belts, mixing vessels, application equipment, or storage areas where intense friction or material movement occurs.

Operational staff should be trained in the basic principles of measurement and interpretation of results. For example, static charge values above 1,000 V already pose a risk of igniting flammable vapors, while values above 5,000 V can cause serious damage to sensitive electronic components or impair coating quality. Measurements should be carried out using standard test methods, and the results documented within the internal safety management system. If limits are repeatedly exceeded, a review of technical measures, such as grounding or the installation of ionization devices, must be conducted.

Specifics of Storage and Handling of Flammable Coatings and Inks

Storage and handling of flammable coatings and inks require special attention due to the risk of ignition caused by static electricity. The basic rule is to store these materials in closed, grounded containers that minimize the generation of static charge. When transferring or mixing, it is essential to use conductive hoses and funnels that are properly grounded to prevent charge accumulation. Furthermore, it is important to adhere to the maximum permissible flow rates of liquids, which are determined based on the viscosity and flammability of the material—typically ranging between 1–3 m/s.

In areas where flammable substances are handled, adequate ventilation must be ensured, and only explosion-proof electrical equipment should be used. Floors should be made of antistatic materials, and staff should wear antistatic clothing and footwear. When handling powder coatings, care must be taken to prevent dust swirling, which increases the risk of explosion. All these procedures should be part of internal regulations and regularly checked as part of safety audits.

Safety is no accident – consult the experts

Every raw material for coatings and inks requires an individual approach to safety. GCG Group provides detailed Safety Data Sheets (SDS) and technical support for all supplied products to optimize storage, handling, and application. Contact us for a consultation on specific risks in your operations. Get in touch – or browse our catalog of over 1,300 products right away.