The Right Way to Compare Safety Data Sheets

A revised Safety Data Sheet can change how a substance is stored, handled, controlled or transported. The job is not simply to find textual differences. You need to decide whether the new information changes the risk in your workplace and what action follows.

An SDS describes a product's hazards and gives information needed for safe handling and use. It supports a COSHH assessment, but it is not the assessment itself. HSE makes that distinction clear in its Safety Data Sheets guidance.

1. Make sure you are comparing the same product

Before comparing revisions, check Section 1 of both documents. Match the product identifier, supplier, product code, recommended uses and emergency contact details. Then check Section 3 for the substance or mixture information.

Do not merge information from SDS documents covering different manufacturers, grades, concentrations or formulations. A newer document for a similar trade name is not automatically a replacement for the product you use.

2. Record the document details

Create a simple comparison record containing:

• the product and supplier;
• the previous issue date, revision number and language;
• the new issue date, revision number and language;
• when the revised SDS was received;
• who reviewed it;
• the sections that changed;
• the decision and actions arising from the review.

Section 16 normally contains the revision date and may summarise changes, but do not rely on that summary alone. Review the safety-critical sections directly.

3. Compare the hazards first

Start with Section 2. Look for changes to:

• hazard classifications;
• signal words;
• hazard and precautionary statements;
• pictograms;
• supplemental hazards or information about other risks.

A change here may affect labels, storage arrangements, emergency procedures, worker information and the controls in your COSHH assessment. Our guides to Danger and Warning signal words and H-phrases and P-phrases explain how these elements fit together.

4. Review composition and exposure controls

Compare Section 3 for changes in ingredients, concentration ranges or disclosed hazardous components. Then check Section 8 for new or changed workplace exposure limits, engineering controls, respiratory protection, gloves, eye protection and other personal protective equipment.

A different concentration range can change the classification or the level of control needed. A new glove material or respirator recommendation does not mean PPE is the only answer; COSHH requires exposure to be prevented or adequately controlled, with engineering and organisational controls considered before relying on PPE.

5. Check handling, storage and physical behaviour

Review Section 7 for incompatible materials, storage temperatures, ventilation and handling precautions. Compare Section 9 for changes to physical state, flash point, vapour pressure, pH and other relevant properties. Check Section 10 for stability, dangerous reactions and conditions to avoid.

These changes may affect storage segregation, transfer equipment, ignition controls, spill containment or the way a task is carried out. They should be assessed against the actual quantity, frequency, process and people exposed at your workplace.

6. Compare emergency and health information

Sections 4, 5 and 6 cover first aid, firefighting and accidental release. Sections 11 and 12 cover toxicological and ecological information. Check whether the revised SDS changes the expected symptoms, exposure routes, firefighting media, spill response or environmental precautions.

Update emergency instructions and training if the practical response has changed. Workers need the current action, not merely access to the new PDF.

7. Check disposal, transport and regulatory information

Review Section 13 for disposal changes, Section 14 for transport classification and Section 15 for regulatory information. A change to the UN number, proper shipping name, class or packing group can affect packaging, marks, labels and transport documents. See our SDS shipping check for the full workflow.

8. Resolve discrepancies instead of choosing between them

If the new SDS appears incomplete, contradicts the label or conflicts with the previous version, contact the supplier. Record the query and the answer. Do not combine whichever entries seem most cautious or most convenient: that can produce a document that describes no real formulation.

Keep the superseded SDS according to your record-retention needs, but clearly mark it as superseded so workers do not use it as the current operational document.

9. Turn the comparison into workplace action

A material change should trigger a review of the relevant COSHH assessment. Depending on what changed, you may need to:

• change the process, substitution decision or engineering controls;
• update storage, segregation or waste arrangements;
• change PPE specifications;
• revise labels, work instructions or emergency plans;
• brief or retrain workers;
• replace the SDS in every controlled location and digital library;
• check whether health surveillance or exposure monitoring remains suitable.

HSE's COSHH risk-assessment guidance says assessments and controls should be reviewed when substances, processes or other workplace conditions change.

A repeatable SDS comparison checklist

• Confirm both SDS documents cover the exact same product.
• Record the issue dates, revision numbers and reviewer.
• Compare Sections 2, 3, 7, 8, 9 and 10 first.
• Review emergency, health, environmental, disposal and transport changes.
• Ask the supplier to resolve missing or contradictory information.
• Document the workplace decision and assigned actions.
• Update the COSHH assessment, controls, training and SDS library.

Your comparison record should show which revision was reviewed, what changed and how those changes were applied at your workplace.