SDS vs MSDS: what is the difference, and are old MSDSs still valid?

A material safety data sheet (MSDS) and a safety data sheet (SDS) do the same job: they tell people how to handle a hazardous product safely. The difference is the system behind them. MSDSs belong to the national systems used before the Globally Harmonized System (GHS). SDSs follow the GHS format and classification rules, which Canada and the US both adopted.

What changed

• Format: a WHMIS 1988 MSDS in Canada had nine required sections, and a US MSDS had no set format at all. An SDS has 16 sections in a fixed order in both countries.
• Classification: WHMIS 1988 used classes A to F (compressed gas, flammable and combustible, oxidizing, poisonous and infectious, corrosive, dangerously reactive). GHS-based rules use hazard classes and categories with set criteria.
• Symbols and wording: the old WHMIS symbols in circles and the hatched border were replaced by GHS pictograms in a red diamond, with a signal word and standard hazard and precautionary statements.
• Expiry: under WHMIS 1988, suppliers had to update an MSDS every three years. Suppliers no longer have a fixed schedule; they must keep the SDS accurate. In some provinces and in federal workplaces, employers must still check every three years that they have the latest SDS. See how often you need to update an SDS.

Is an MSDS still valid?

Not for a supplier, in either country. In the US, OSHA's 2012 update to the Hazard Communication Standard required the 16-section SDS. Its phase-in finished in 2015 for manufacturers, importers and distributors, and in 2016 for employers. In Canada, WHMIS 2015 replaced WHMIS 1988, and the transition for employers ended in December 2018. Canadian SDSs have since had to be updated again for the HPR amendments, mandatory since December 2025.

So if your workplace binder still contains MSDSs, those products are very likely documented with out-of-date information. Ask each supplier for the current SDS. If a product is no longer made or used, remove it from the active binder.

Why people still say MSDS

Mostly habit. Many people still search for "MSDS", and some suppliers keep the term in file names and websites. What matters is the document itself: a current SDS has 16 numbered sections, GHS pictograms, a signal word, and a recent revision date.

Before you throw old sheets away

In the US, OSHA's records rule (29 CFR 1910.1020) treats safety data sheets as employee exposure records. They do not have to be kept for a set period, as long as some record of the chemical's identity, where it was used and when it was used is kept for at least 30 years. In Canada, record-keeping duties are set by each province or territory. Check your own rules before you discard archived sheets.

Quick check of your SDS library

1. Does any sheet say "Material Safety Data Sheet", or have fewer than 16 sections?
2. Does it still use the old WHMIS circle symbols or a hatched border?
3. In Canada, is it dated before 15 December 2022 and not reviewed since?
4. Is the French version missing for a Canadian workplace?

Any "yes" means the sheet should be replaced. If you have many, our SDS library service collects and checks them for you.

General information, not legal advice. Checked against the official sources above on 10 October 2026. Rules change: for your own products, ask for a spot-check.