ADR and GHS — How to Correctly Label Hazardous Substances?

Companies that store, transport, or use hazardous substances must apply labeling that complies with current EU regulations. This applies to chemical warehouses, laboratories, and production plants, as well as logistics, technical, and service facilities.

In practice, two labeling systems are most commonly used:

• GHS/CLP — used for the classification and labeling of hazardous substances in the workplace,
• ADR — governing the transport of dangerous goods by road.

Although both systems use similar warning pictograms, they serve different functions and are subject to different legal requirements. Incorrect labeling can lead to problems during inspections, fines, transport being held up, and above all — real hazards to workers and the surrounding environment.

In this article, we explain step by step how the two systems differ, what each pictogram means, what dimensions the regulations require, and where and how to apply labeling to maintain full compliance with the standards.

What is GHS and CLP labeling?

The GHS (Globally Harmonized System) is a global system developed by the UN for classifying and labeling chemical substances, aimed at standardizing hazard communication regardless of the user's country or language. In the European Union, this system was implemented through the CLP Regulation (EC) No 1272/2008 (Classification, Labelling and Packaging), which has been fully in force since 2015 for both substances and chemical mixtures.

GHS labeling is used, among other places, on:

• chemical packaging,
• containers and tanks,
• chemical cabinets,
• doors of technical rooms,
• hazardous substance storage areas.

In the workplace, GHS labeling helps quickly identify hazards and increases the safety of employees and service crews — the pictograms are visually recognizable, so they work even where workers speak different languages.

Meaning of the individual GHS pictograms

The CLP/GHS system uses nine standardized graphic pictograms. Each has the shape of a square set on its point (a diamond), with a black symbol on a white background, surrounded by a red border.

Pictogram	Symbol	Meaning
GHS01	Exploding bomb	Explosive materials and mixtures
GHS02	Flame	Flammable substances
GHS03	Flame over circle	Oxidizing substances
GHS04	Gas cylinder	Gases under pressure
GHS05	Corrosion (acid)	Corrosive substances, damaging to metal and skin
GHS06	Skull and crossbones	Highly toxic substances
GHS07	Exclamation mark	Irritating, harmful substances
GHS08	Health hazard (human silhouette)	Long-term health hazard, e.g. carcinogenicity
GHS09	Fish and tree	Hazard to the aquatic environment

Note: some pictograms are mutually exclusive on a single label — for example, when GHS06 (acute toxicity) is used, GHS07 is not applied at the same time for the same hazard, because the more severe hazard "overrides" the weaker one.

What is ADR labeling?

ADR (the European Agreement concerning the International Carriage of Dangerous Goods by Road) governs the road transport of dangerous goods across Europe. The agreement was drawn up in 1957 and is regularly updated — amendments are currently introduced every two years, so it's worth periodically checking that transport labeling in use complies with the current version of the regulations.

The ADR system covers the labeling of vehicles, containers, and packaging used when transporting dangerous materials. Unlike GHS, which primarily concerns the workplace and storage, ADR focuses on logistics and transport — covering classification, packaging, labeling, and transport documentation.

ADR hazard classes

Class	Type of hazard
1	Explosive materials and articles
2	Gases (compressed, liquefied, dissolved under pressure)
3	Flammable liquid materials
4.1–4.3	Flammable solids, substances liable to spontaneous combustion, substances that emit flammable gases in contact with water
5.1–5.2	Oxidizing substances and organic peroxides
6.1–6.2	Toxic and infectious substances
7	Radioactive materials
8	Corrosive materials
9	Miscellaneous dangerous substances and articles

ADR classes do not directly correspond to GHS hazard categories — both classifications indicate the nature of the hazard, but they are based on separate numbering systems and separate documentation requirements. This is why many products require simultaneous labeling under both systems: GHS on the unit packaging and ADR on the bulk packaging or vehicle.

GHS vs. ADR — key differences

This is one of the most common issues when labeling warehouses and chemical storage zones — which labeling to apply, and where.

Criterion	GHS / CLP	ADR
Scope of application	Workplace, storage, use of substances	Road transport of dangerous goods
Legal basis	CLP Regulation (EC) No 1272/2008	ADR Agreement (updated every 2 years)
Shape of the mark	Square on its point, white background, red border	Diamond (square rotated 45°), usually with the class number at the bottom
Where it is placed	Packaging, tanks, chemical cabinets, rooms	Vehicles, containers, transport packaging
Who it primarily concerns	Employers, warehouse staff, lab technicians	Carriers, freight forwarders, drivers

In practice, many companies need both systems at the same time — especially warehouses, logistics centers, production plants, and technical facilities, where a substance is both stored and shipped onward.

Label dimensions — what do the regulations say?

The size of GHS labels and pictograms is strictly defined by regulation and depends on the packaging capacity:

• Packaging up to 3 liters — label min. 52 × 74 mm, pictogram min. 10 × 10 mm,
• Packaging 3–50 liters — label min. 74 × 105 mm, pictogram min. 23 × 23 mm,
• Packaging 50–500 liters — label min. 105 × 148 mm, pictogram min. 32 × 32 mm,
• Packaging over 500 liters — label min. 148 × 210 mm, pictogram min. 46 × 46 mm.

In addition, each hazard symbol should cover at least 1/15 of the label's surface area, but never less than 1 cm². Choosing the wrong size is one of the most common errors found during inspections — so when ordering, it's worth checking the label size against the capacity of the packaging in use right away.

Where should GHS and ADR labeling be applied?

Proper labeling should be visible before entering a hazard zone, placed at eye level, and adequately lit.

GHS labeling:

• chemical warehouses,
• laboratories,
• technical rooms,
• chemical cabinets,
• storage zones,
• workshops,
• production halls.

ADR labeling:

• transport vehicles,
• containers,
• loading areas,
• logistics ramps,
• dangerous goods shipping and receiving areas.

Many facilities use the following simultaneously:

• ISO 7010 warning signs,
• GHS labeling,
• ADR placards,
• fire safety (PPOŻ) marking,
• health & safety (BHP) and evacuation instructions.

A complete facility labeling system therefore combines all these elements — a GHS sign on a chemical cabinet alone is not enough if the same room lacks evacuation route markings compliant with the PN-EN ISO 7010 standard.

Consequences of missing or incorrect labeling

A lack of GHS or ADR labels compliant with regulations can lead to serious operational and legal consequences:

• Fines and administrative penalties — in Poland, their amount is regulated by dangerous goods transport laws and enforced by the Road Transport Inspectorate,
• Transport being held up — a vehicle may be detained until the irregularities are corrected, generating costs and delays in the supply chain,
• Negative health & safety / fire safety audit results — outdated or illegible labeling is one of the most commonly cited issues during workplace inspections,
• Real risk to health — employees and emergency services lose the ability to quickly identify a hazard in an emergency situation.

How to ensure labeling compliance? Audit checklist

During a labeling audit, it's worth checking:

• whether the pictograms in use are current and comply with the applicable version of the regulations,
• whether the labeling is clearly visible and undamaged,
• whether the signs correspond to the actual hazards present in a given zone,
• whether the label size matches the packaging capacity,
• whether the materials are resistant to working conditions (moisture, UV, abrasion, temperature changes),
• whether ADR transport labeling complies with the current, biennially updated regulations,
• whether GHS, ADR, fire safety, and ISO 7010 labeling in the facility are coordinated to complement one another.

For industrial and logistics facilities, it's worth regularly updating labeling as processes, storage methods, or substance classifications change — not just once, at the time the facility is commissioned.

Frequently Asked Questions (FAQ)

Do you need to use GHS and ADR labeling at the same time?

Yes, if a substance is both stored and transported. GHS covers the unit packaging and storage zone, while ADR covers the bulk packaging and the vehicle. In practice, both labels operate in parallel at different stages of the substance's handling.

How often are ADR regulations updated?

The ADR Agreement is amended on a two-year cycle. This means transport placards and labels should be checked for compliance with the latest version of the regulations whenever there is a major change to the fleet or product range.

How does GHS labeling differ from health & safety (BHP) signs?

GHS pictograms relate exclusively to the classification of chemical hazards and have a standardized, international form (diamond, red border). BHP signs cover a broader range of workplace hazards — mechanical, electrical, evacuation-related — and come in different shapes and colors depending on their function (prohibition, mandatory action, warning, information).

What penalties apply for missing proper labeling?

Depending on the violation, these can include fines, administrative penalties imposed by the Road Transport Inspectorate, vehicle detention until irregularities are corrected, and, in the case of health & safety inspections, post-inspection orders requiring immediate correction of labeling.

What materials should ADR/GHS labels and placards be made of?

Materials resistant to moisture, UV radiation, abrasion, and temperature changes are recommended — most commonly aluminum, rigid PVC, or reinforced self-adhesive film, depending on where they will be mounted (vehicle, hall, outdoor warehouse).

Professional ADR, GHS, and ISO 7010 Labeling — StoreForSigns

At StoreForSigns you'll find a complete range of safety labeling tailored to the requirements of your industry:

• safety signs compliant with ISO 7010,
• ADR labeling for vehicles, containers, and packaging,
• GHS pictograms in all required sizes,
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• solutions for warehouses, laboratories, commercial, and industrial facilities.

We offer production in Europe, durable materials resistant to harsh conditions, fast delivery across the EU, and the option to order single units or custom items — tailored to the specific packaging capacity and facility requirements.

See the full range of GHS hazard signs → Check out ADR transport labels and placards →

Not sure what labeling is required at your facility? Contact our advisor and get a free quote tailored to your industry.