CLP / GHS Hazardous Chemical Packaging Labels: 3 Practical Boundaries—Pictograms / H Statements / Minimum Net Content—and the 3 Documents Printers Should Request First

In August 2025, a client selling industrial solvents sent us a set of label artwork with the note: “Just follow our previous sample.”

The sample was from a label run they had ordered three years earlier. The customer had changed, although the chemical was the same; only the product name had changed.

We followed the sample. After production, the client signed off on the labels, which were then shipped to Europe.

Two months later, the client forwarded an email from a German customer titled “Non-compliant packaging labels; stop shipments immediately.” The reason was brief: the acute toxicity classification in the product SDS was Acute Tox 3 (Category 3), but the label showed the environmental hazard pictogram without the skull-and-crossbones.

The root cause was not our printing process—we had followed the artwork approved by the client. The root cause was that the sample had not been reviewed again alongside the product. The client had changed the product name, the SDS had been updated, and the relationship between the classification and the label had changed, while the pictograms and H statements printed on the label remained three years out of date.

This article examines the three practical boundaries of chemical labels and identifies the three documents a printer should request first when accepting such an order.

First, one clarification: CLP and GHS are two names for the same system

Many customers use the two terms interchangeably, and printers are often caught doing the same. In simple terms:

Therefore, when a customer specifies “GHS” or “CLP,” the practical difference mainly concerns two issues:

• Toxicity—GHS originally did not include acute toxicity classification. CLP added 5 acute toxicity categories. If a product has acute toxicity, the customer’s instruction to follow “GHS” is incomplete, and CLP must be applied.
• Language—CLP requires the label language to be that of the Member State where the product is sold. Within the EU, the current general requirement is the target-country language plus English (French in France, Polish in Poland, and English alone may be used in English-speaking markets).

Boundary 1: Pictograms—simplest in printing, but often the most damaging in legal terms

Pictograms are black-and-white diamond-shaped icons covering 9 categories. Technically, there is no difficulty in printing them once the printer receives approved artwork.

The real difficulty lies in which ones to use and how to arrange them.

Several points are particularly easy to overlook:

• Priority—If a product meets the criteria for multiple pictogram categories, CLP establishes a clear priority order: gases > explosives > oxidizers > flammable substances > self-reactives > organic peroxides > acute toxicity > corrosives > health hazards > environmental hazards. Those appearing earlier must be printed, while those appearing later may be omitted.
• Not all categories can appear together—For example, flammable solids and oxidizers cannot be displayed together.
• Minimum dimensions—The minimum side length of a pictogram diamond is 15 mm. If two or more pictograms are to be arranged side by side, the minimum label size is determined by the pictograms rather than by the printer.
• Red background—Pictograms must use black symbols on a white background with a red diamond border. The border cannot be changed to a brand color, and the colors cannot be reversed.

The last point is where clients most often ask printers to “optimize” the label. Many clients find the red border too conspicuous and want to replace it with gold or dark gray to achieve a more premium appearance.

On one occasion, the client was a fragrance ingredient manufacturer with a high-end product line. The sales representative said, “Consumers will not see the pictograms anyway, so it should be fine to make them smaller, right?”

We replied with three words: Non-compliant.

The minimum pictogram size is not an aesthetic preference; it is a legal requirement. Below 15 mm, emergency responders may be unable to recognize the pictogram while wearing gloves or viewing it in a moving vehicle. This dimensional margin is not available for design purposes.

Another requirement that is frequently overlooked is that the red border of a pictogram must not be changed to another color because of production considerations. In four-color printing, the solid red area must have sufficient opacity; otherwise, the border may appear blurred under strong lighting and visually fail to meet the requirements. A spot color red is more reliable than a four-color red.

Boundary 2: H statements—many options, but selecting the wrong one creates more problems than an incorrect pictogram

H statements are hazard statements, such as “Flammable liquid and vapor” (H225), “Toxic if swallowed” (H301), or “Toxic to aquatic life with long lasting effects” (H411).

Printers are not responsible for selecting them, but printers must know how to verify whether the client has selected them correctly, because printing errors frequently occur at this stage—for example, when the H code is correct but the wording comes from an obsolete version.

Three common printing errors are:

There is also a practical point regarding combined statements: if the client provides a single block of combined wording, confirm that every statement code appears within it. On one occasion, we received artwork stating “H302+H312+H332 Harmful if swallowed, in contact with skin or if inhaled.” It looked entirely standard, but the client had omitted the “if inhaled” wording corresponding to H332. This error cannot be detected at proofing because the sentence still reads naturally.

The most effective verification method a printer can use is straightforward: obtain the client’s H statement list and compare each statement word for word against the official current-version text, without relying on visual approximation.

Boundary 3: Minimum net content—a hard limit derived entirely from package size

This requirement is the easiest to overlook, but it includes one rule that allows no negotiation:

The net content quantity stated on the label must not be less than 1/3 of the net content of the substance packaged inside.

Although this appears unusual, the logic is that emergency responders need to know approximately how much material is inside without unpacking the entire package. An approximate indication is sufficient, so a value equal to one-third is permitted, but exact precision is not required.

The practical consequence is: the larger the package, the smaller the label may be.

Conversely, if the client specifies a fixed, small label size for a 30 kg drum, the minimum net content stated on the label is locked at 10 kg. The client must therefore either state “30 kg” or divide the product into smaller packages with corresponding labels. There is no third option.

This rule is rarely triggered in industrial chemical packaging, but it is very common in laboratory reagent packaging and e-commerce small-package portioning.

Consider a real example we encountered: a client sold Solution A in 5 kg containers and wanted to divide it into 500 g bottles for direct e-commerce shipment, with one label on each bottle. For a 500 g bottle, what net content should be stated under CLP?

The minimum is 167 g because 1/3 of the actual 500 g is 167 g. Stating 500 g is also permissible, but there is no need to state the quantity that precisely. The client wanted to state “Net weight 500 g,” which is fully acceptable under CLP because an exact value may be used. However, simply stating “1 kg” to save effort would be incorrect because the stated value must be no greater than the actual packaged quantity and no less than 1/3 of it.

There is also a closely related practical issue: the method of expressing net content on labels varies between target countries. The EU requires “net content” plus the value and unit, and certain Member States impose additional requirements on unit notation—for example, g / kg for weight and mL / L for volume, with some markets also requiring the ℮ mark. Labels for multi-country exports must be versioned by country.

The 3 documents printers should request first when accepting chemical label orders

If any one of these documents is missing, the printer is merely reproducing artwork and cannot demonstrate its own compliance if an incident occurs.

First: the current SDS. Not the client’s classification conclusion, but the classification and labeling elements in Section 2 of the SDS. This is the single source of truth from which the pictograms, H statements, S statements, and signal word are derived. When a client says, “Follow the old sample,” it is especially important to request the current SDS, because the SDS is updated annually and the label must remain aligned with it.

Second: confirmation of label dimensions and languages. The countries where the product will be sold determine the languages and CLP variants. This confirmation must identify which label version is used for each country, whether multilingual artwork is required, the label dimensions, and whether sufficient pictogram space is available. These details determine plate preparation and printing because multilingual labels require multiple versions on the same base stock, making them a completely different production job.

Third: regulatory declarations and allocation of responsibility. It must identify who is responsible for the final classification (the EU responsible party / importer / brand owner), who is the label provider, and whether the printer’s role is merely to print the client-approved artwork or to provide compliance advice. This must be recorded in the quotation or a contract appendix.

Our factory practice is to quote only after all three documents are available. If the SDS is missing, the quotation states, “Printing according to the client-approved artwork; regulatory compliance is the responsibility of the client,” followed by a request for the client to confirm this by email. That sentence has helped us avoid several disputes.

Further reading

The following topics belong to the same compliance framework as this article:

• 4 Types of Prohibited or Restricted Claims Under China’s Advertising Law—terms such as “non-toxic” and “natural” on chemical labels follow the same underlying legal logic
• 3 Regulatory Requirements for Printing Cosmetic Registration Numbers on Packaging—the regulatory significance of placement and contrast is equally relevant
• 3 Practical Risk Boundaries for Packaging Materials: Migration / Heavy Metals / Odor—the ink and substrate on a label and the chemical substance it identifies appear at opposite ends of the same test report
• 4 Packaging Compliance Requirements for Exports to the EU—another EU compliance line that exists alongside CLP
• 3 Practical Classifications of Packaging Test Reports—which report chemical customers should request when requesting documentation