WHMIS supplier label and SDS discrepancy: what receiving teams should do

The name on a drum matches a purchase order, but the supplier label and safety data sheet (SDS) do not appear to describe the same hazards. The right response is not to select whichever document seems more plausible. Receiving and safety teams need to establish the product's identity, prevent unsafe use while the mismatch is assessed, and obtain a reliable answer from the supplier.

This is an exception-handling guide for Canadian workplaces, not an introduction to WHMIS. For the overall system, see the Canadian WHMIS explainer. Federal law addresses supplier classification and hazard communication; the employer's workplace duties depend on the applicable provincial, territorial or federal occupational health and safety regime. Check that regime before describing a step as a universal legal requirement.

First confirm that the documents concern the same product

Compare the product identifier, manufacturer or importer, supplier details, formulation or concentration where shown, and the SDS issue or revision date. A distributor may send an SDS for a similarly named product, an older formulation, or a different package size. A supplier label may also be damaged or missing information. Do not assume a changed pictogram automatically means a supplier error: classification can change with new information and products can be reformulated. The question is whether the label and SDS accompanying this shipment communicate consistent information for this product.

Health Canada's guidance on WHMIS supplier requirements explains federal label and SDS content obligations. The supplier identifier and product identifier are useful starting points for a mismatch investigation. An internal receiving checklist should compare the documents, not attempt to reclassify a hazardous product from scratch.

Put the affected shipment on an appropriate hold

If the discrepancy could affect safe handling, storage, emergency response or worker instruction, keep the product from routine use until a competent person resolves it. Identify the container and location, restrict access where necessary, and communicate the issue to the supervisor and people who may handle it. The hold should be proportionate to the hazard; an emergency response may require different immediate action than an administrative identifier error.

Do not replace a supplier label with a guessed workplace label to make the inventory appear complete. Nor should a worker rely on a generic SDS from an internet search without confirming it covers the supplied material. Follow the workplace's spill, exposure and emergency procedures if an incident has already occurred. The discrepancy log is a control record, not a substitute for those procedures.

Ask the supplier a precise question

Send the supplier the product identifier, batch or lot where relevant, purchase reference, photograph of the label and copy of the SDS received. State exactly which fields differ: for example, the identifier, hazard classification, pictogram, signal word, precautionary statement or emergency number. Ask the supplier to confirm the correct label and SDS for the supplied product and whether any interim precautions apply. Retain the written reply and corrected documents.

An answer such as “use the latest SDS” may be insufficient if the container still has a conflicting hazard label. Ask how the supplier will correct the label or whether the shipment should be returned. Health Canada's supplier guidance is the primary reference for what a supplier must provide; local workplace rules govern what the employer must do with the product on site.

Check the workplace's own WHMIS obligations

Ontario's WHMIS employer guidance says employers buying hazardous products must obtain supplier SDSs, subject to specified exceptions, and make relevant SDS information available to workers. It also describes workplace labelling and worker education. That is an Ontario example, not a claim that the same provision and wording applies identically in every Canadian jurisdiction.

If the corrected hazard information changes the controls workers were taught, review the training and site instructions before releasing the material. The receiving team may need to update chemical inventories, storage segregation, PPE guidance, exposure controls or emergency information. A revised document in a repository does not prove affected workers know what changed.

Record the decision to release or return

An effective exception record has a product and shipment identity, the specific discrepancy, who noticed it, when it was reported, whether use was stopped, what the supplier said, which documents replaced the originals, and who authorised the outcome. Preserve the superseded documents for an audit trail while making the current SDS easy for workers to find. Record whether the product was released, relabelled by an authorised process, returned or disposed of under the applicable rules.

The reviewer should confirm that the corrected documents agree and that any workplace changes have been made. If the supplier cannot explain a material mismatch, escalation to a competent safety or regulatory specialist is more defensible than marking the ticket “resolved” because an email was received.

Example: receiving a cleaning chemical

A warehouse receives cartons of a cleaning chemical whose label warns of serious eye damage, while the supplied SDS lists a milder eye-irritation classification. Receiving logs the mismatch, identifies the cartons, and prevents issue to the cleaning team. The buyer asks the supplier for the correct documents for the exact product and lot. Once the supplier confirms a formulation change and sends a corrected label and SDS, the employer reviews storage, PPE and worker instructions before release. The record links the shipment, supplier answer, corrected documents and release decision.

The example illustrates a process, not a legal determination of the product's classification. Only the supplier's competent classification and the applicable legal framework can settle the hazard communication question.

Evaluate a system for exception control

For teams with many sites or products, assess whether a document system can link the received SDS and label to the exact product, preserve previous versions, show an unresolved exception to users and support a release decision. Test a real mismatch scenario. A searchable SDS library is useful, but it should not silently hide an unresolved discrepancy.

The Complys Canada WHMIS and SDS software page is the mapped commercial page for evaluating a broader record workflow. Verify actual product functions before relying on them. This guide does not claim Complys can classify chemicals, validate supplier labels automatically or make legal release decisions.