OSHA Hazard Communication Standard and GHS: A Guide to Chemical Safety Pictograms

The US Occupational Safety and Health Administration (OSHA) Hazard Communication Standard (HCS), codified under 29 CFR 1910.1200, governs how chemical hazards are communicated in American workplaces. It is based on the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS). Labels, pictograms and Safety Data Sheets are essential tools for preventing accidents and protecting workers.

Introduction

The OSHA Hazard Communication Standard (HCS) is a US regulation designed to ensure that workers receive the information they need about hazardous chemicals present in their workplaces.

Revised in 2012 to align with the third revision of the GHS, the standard was amended again in 2024, primarily to align with the seventh revised edition of the international system. The amendment entered into force on 19 July 2024. In January 2026, OSHA extended several compliance deadlines by four months.

The main methods of communicating chemical hazards include:

Chemical product labelling.
Hazard pictograms and hazard statements.
Safety Data Sheets (SDS).
Worker training.
A written hazard communication programme for workplaces subject to the regulation.

Important: The OSHA standard applies in the United States. It is not, by itself, the applicable regulation for businesses operating in Morocco.

The GHS: Principles and Objectives

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is an international system developed under the auspices of the United Nations.

Its main objectives are to:

Harmonise the classification of chemical hazards.
Standardise label elements.
Improve workers’ understanding of chemical risks.
Strengthen the protection of human health and the environment.
Promote consistency in international chemical trade.

The GHS establishes standardised pictograms, signal words, hazard statements and precautionary statements.

However, specific legal obligations depend on the regulations adopted by each country or region. OSHA requirements in the United States are therefore not identical to those under the European Union’s CLP Regulation.

The Nine GHS Pictograms

The GHS uses nine standardised pictograms. Each consists of a black symbol on a white background, enclosed within a red diamond-shaped border. Each pictogram corresponds to specific hazard categories.

Pictogram	Name	Main hazards
💀	Skull and crossbones	Severe acute toxicity that may cause death or serious poisoning.
🔥	Flame	Flammable products, pyrophoric substances, certain self-reactive substances and other categories presenting fire hazards.
⭕🔥	Flame over circle	Oxidising substances that can intensify a fire.
💥	Exploding bomb	Explosives, certain self-reactive substances and certain organic peroxides.
🗜️	Gas cylinder	Gases under pressure, including compressed, liquefied and dissolved gases.
🧪	Corrosion	Metal corrosion, severe skin burns and serious eye damage.
❗	Exclamation mark	Skin or eye irritation, less severe acute toxicity and certain other harmful health effects.
🌳🐟	Environment	Hazards to aquatic organisms and aquatic ecosystems.
👤	Health hazard	Certain cancer risks, genetic mutations, reproductive toxicity, respiratory sensitisation and specific target-organ effects.

The gas cylinder pictogram identifies gases under pressure. The serious health hazard pictogram depicts a human silhouette with a starburst on the chest.

The environmental pictogram is part of the GHS, but OSHA does not require it under its Hazard Communication Standard because environmental hazards fall outside the scope of that standard. It may nevertheless be used where other applicable regulations require it.

Important: A pictogram alone does not provide a complete assessment of a chemical’s hazards. Users must also read the product name, hazard statements, precautionary statements and Safety Data Sheet.

Safety Data Sheets (SDS)

A Safety Data Sheet (SDS) provides information needed to identify hazards and establish safe handling, storage, prevention and emergency response procedures.

The harmonised GHS format contains 16 sections:

Identification of the substance or mixture and the supplier.
Hazard identification.
Composition and information on ingredients.
First-aid measures.
Firefighting measures.
Accidental release measures.
Handling and storage.
Exposure controls and personal protection.
Physical and chemical properties.
Stability and reactivity.
Toxicological information.
Ecological information.
Disposal considerations.
Transport information.
Regulatory information.
Other information, including the revision date.

The relevant sections should be consulted according to the task and the identified risks. Section 8 is particularly useful for determining exposure controls and selecting appropriate personal protective equipment. Sections 4, 5 and 6 are essential for emergency preparedness.

Language requirements and arrangements for making SDS available depend on the applicable legislation. In the United States, OSHA requires the relevant information to be available in English, while additional language versions may also be provided.

Employer Responsibilities Under OSHA

In workplaces covered by 29 CFR 1910.1200, employers must, among other requirements:

Maintain access to SDSs for hazardous chemicals present in the workplace.
Ensure proper labelling of containers in accordance with applicable requirements.
Train workers on chemical hazards, label interpretation, SDS use and preventive measures.
Establish a written hazard communication programme.
Update information and training when new hazards are identified.

Compliance Deadlines Under the 2024 Revision

Following the extensions announced in January 2026, the main OSHA compliance deadlines are as follows:

Requirement	Deadline
Substance evaluations by manufacturers, importers and distributors	19 May 2026
Workplace label updates, hazard communication programme updates and worker training for substances	20 November 2026
Manufacturer, importer and distributor compliance for mixtures	19 November 2027
Workplace label updates, hazard communication programme updates and worker training for mixtures	19 May 2028

These deadlines apply to the US regulatory framework and must not be presented as legal deadlines applicable in Morocco.

Application in Morocco

In Morocco, chemical risk prevention must be organised in accordance with applicable laws and regulations, including the relevant provisions of Law No. 65-99 on the Moroccan Labour Code concerning occupational hygiene and employee safety.

Businesses must identify hazardous products, assess the risks associated with their handling, inform workers and implement appropriate preventive measures.

In this context, GHS pictograms and Safety Data Sheets are valuable practical tools for:

Identifying chemical hazards.
Establishing safe handling and storage conditions.
Selecting appropriate personal protective equipment.
Preparing emergency procedures.
Training workers in chemical risk prevention.
Organising the management of spills and hazardous waste.

Moroccan businesses exporting to the United States or the European Union must also comply with the requirements applicable to their destination markets. Compliance with OSHA or the European CLP Regulation depends on the scope of each regulatory framework and does not replace applicable national obligations.

Conclusion

Communicating chemical hazards is a fundamental element of occupational risk prevention. GHS pictograms enable workers to recognise major hazards quickly, while Safety Data Sheets provide the information needed for safe handling, storage and emergency response.

For HSE professionals, understanding these tools supports risk assessment, the selection of protective measures and effective worker training. Their use must always take account of the regulations applicable to the country, industry and product concerned.

OSHA Hazard Communication Standard & GHS: Safety Pictograms