GHS/CLP: Minimum Font Sizes for Labels (and understanding the proposed changes from points to millimetres)

GHS/CLP Regulations – Revision to Label Specifications

In 2022, the EC advised that the Classification, Labelling and Packaging of chemicals (CLP) regulation was being revised and that this would impact the requirements of labels in order to make them more readable for consumers and end users. A new framework of specific rules that cover how labels should be formatted was introduced.

On the 18th December, 2023, outcomes of further meetings between the European Parliament and the European Council  were published whereby everything was provisionally agreed at technical level, apart from 4 points which were left for agreement.

The CLP Legislative Act was finally passed in a decisive vote held on 23rd April 2024, receiving overwhelming support from MEPs, with 533 in favor, 11 against, and 65 abstentions.

The passing of this vote confirms the text agreed between the co-legislators and ushers in substantial changes to chemical label formatting and minimum font sizes, as well as the broader use of digital labels and booklet labels.

The ‘Partial Legal-Linguistic Finalisation’ text is available to download here: TA-9-2024-0296_EN

Ensure to read the small print very carefully before deciding if/how this applies to your business – to be completely certain, you may want to wait for the pdf version.


Proposed Obligatory Formatting Rules

The new formatting rule for labels are:

  • The text must be printed in black and the background of the text should be white;
  • A single font must be used that is easily legible and without serifs;
  • The letter spacing must be appropriate for the selected font to be comfortably legible;
  • The distance between two lines must be equal, or above, 120% of the font size – for example, a 20 point size font must have leading (line spacing) of 24 point, or above;
  • The font size of regulatory information must be as the following table, dependent on package capacity.

GHS CLP minimum font sizes table points 2024


Measuring Font Sizes

When measuring fonts, we don’t usually deal with the metric measurement system – typographic units are measured in points and font sizes are usually measured from the top of the ascender to the bottom of the descender – this is the full font height/size.

Previously, the EC have specified the changes to font sizes in points, however, the latest amendments to text sizes are specified in x-height (the height of the lower-case x) in millimetres.  This is probably because it is more practical, in real-life instances, to measure in millimetres rather than points, and also because the X-height of fonts differ from one font to the other.

The point size of a font includes 3 main parts:

X-HEIGHT – the height of the lowercase “x” character.

ASCENDERS – lines that extend above the base “x” character (as with ‘h’).

DESCENDERS – lines that extend below the base “x” character (as with ‘g’).


ghs clp minimum text font height x-height for labels measurements


It is important to note that all fonts DO NOT have the same the x-height – even when they are the same point size.  The x-height of fonts can vary considerably, and this can have a great affect on the readability of the text. Lowercase letters in fonts with larger x-heights, such as Veranda and News Gothic appear larger on the whole and are easier to read.

The following shows three different fonts: all fonts are shown at 20pt, but all have different x-heights.

x-height fonts CLP Eu minimum font sizes

The height of the ascenders and descenders in relation to the x-height of characters also differs from font to font.

For chemical labelling, the text ‘tracking’ (space between letters) and ‘horizontal scale’ (width of letters) should not be reduced as this will make text much harder to read, especially at a distance.


Converting x-height in mm, to Point Size

Converting the point size of fonts to millimetres is not as simple as it would seem, and this is without factoring in the x-height of letters.

Strictly speaking, the term ‘font size’ is misleading, since we don’t define the size of the font when setting the point value in software applications such as Word or InDesign, but rather we specify the body height. Historically, in manual typesetting, the body height was defined by the height of the lead type block on which the actual font face, the printing surface of the type, was moulded.  When Gutenberg set a 12pt font, it was the metal type block and not the printed letter that had a vertical height of 12 points. Hence, the body height is generally bigger than the printed character.

In the age of digital type, the body height is now known as the ‘Em’ and is still an important measure reference in font design – when you enter a 12 pt font size in Word, you define the height of a character’s bounding box which corresponds to the height of the metal body the type was cast on in the days of lead typesetting.

A point is equal to 1/72 of an inch or 0.3527 mm, or 1.333 pixels.  72 points = 1″. Because millimetres and inches are measurements of physical items, they are not suitable to use with digital based applications, so for digital, the pixel the smallest unit used to measure font sizes.


Common fonts at the mandatory sizes

When producing chemical labels in-house, or using labelling software, a non-serif font must be used (a serif is a decorative line or taper added to the beginning and/or end of a letter’s stem, such as in the ‘Times’ font).

Common sans-serif fonts used in the chemical industry, include: Arial, Avenir, Calibri, Frutiger, Futura, Gill-Sans, Helvetica, Myriad Pro, News Gothic, Open Sans, PT Sans, Trebuchet and Veranda.


The attached chart shows these common fonts converted from mm x-height to point size, for the given package capacities.

GHS CLP minimum font sizes in mm and points

Measuring Leading (Line Spacing)

Leading, the vertical space between lines of type, is measured from the baseline of one line of text to the baseline of the line above it (see the font diagram above).  The baseline serves as the invisible line on which most letters sit.

As per the new CLP label formatting rules, the distance between two lines must be equal to, or greater than, 120% of the font size.  For instance, a font size of 20 points requires leading (line spacing) of 24 points, or more.


Implementation Deadlines

The transition dates for updating the information on labels are as follows:

For new products:

    • Updating labels after a change of classification: 18 months after this regulation appears in the Official Journal – EU LEX.
    • Rules for advertisements: 18 months after publication.
    • All label formatting rules (including minimum font sizes) may still be subject to change in the finalised text but we are currently expecting: 24 months after publication.

For products already on the market with label formatting as the existing legislation in the 2 years following EU LEX publication, then it’s fine for 4 years after EU LEX publication.

For products already on the market where the label elements need to change (because of the the changes to the ‘contains’ statement, or the addition of the Endocrine hazards, PBT or PMT classes) then the timescale is shorter – around 3.5 years (See Article 61 for more details).

If the label falls within the biocide or detergent regulations, then it is the timeframe specified  within those regulations take precedence.



How Can Hibiscus Help?

hibiscus plc ghs labelling

Hibiscus Plc has been providing labelling solutions for the chemical and hazardous goods industries for over 40 years.

If you have any questions regarding the new minimum font sizes for labels, don’t hesitate to contact us.

Find out how we can improve your hazard communication compliance – Call us today: 0113 242 4272