An SDS must be readily available to employees for the entire time a hazardous product is in use. After a product leaves your site, keep the SDS on file for 40 years from its last recorded use. This article covers both obligations and what to do when a supplier issues a revised version.
How Long Must an SDS Be Kept According to HSE
COSHH sets out two distinct requirements for SDSs. One applies while a chemical is actively being used. The other takes effect once you've stopped. For any product currently on site, both apply together.
While the Chemical Is in Use
COSHH Regulations requires employers to have a current SDS available for every hazardous substance on site. Employees need to be able to get to it on any shift, without any obstacles in the way.
That means genuinely available, not filed away in a locked office or tucked behind a login screen. Paper folders are fine. Digital systems are fine too, provided staff can bring up any SDS without delay, even if the internet goes down.
If an employee asks for an SDS and you can't produce it, that's a breach of COSHH Regulations. HSE won't accept that it was temporarily unavailable.
After You Stop Using the Chemical
Once a product is no longer in use, the day-to-day access obligation drops away. A separate, longer-term one comes into effect.
Employee Exposure Record: Under COSHH Regulation 10, an SDS is treated as an exposure record for any substance an employee has worked with. HSE requires those records to be held for 40 years from the date of the last recorded entry.
The 40-Year Clock: It starts from the last date any employee was exposed to the substance, not from when the product was purchased or when it left your stores.
What You Need to Hold: Keeping the SDS itself is the simplest way to meet the requirement. If retaining every SDS long-term isn't practical, COSHH permits a substitute record that identifies the substance, where it was used, and the period of use.
The Substitute Record Trap: Many workplaces choose this route but fail to capture the necessary details before discarding the original SDS. Once it's been disposed of, recovering that information is rarely possible. Keeping the SDS avoids the problem entirely.
What to Do When You Receive an Updated SDS
Suppliers issue revised SDSs when a product's composition changes or new hazard information becomes available. When a new version comes in, you can't simply add it to the file and throw out the old one.
- Compare the two versions. Check whether the list of hazardous ingredients has changed between the old SDS and the new one.
- If the composition is the same, the new SDS takes over from the old one. You can dispose of the previous version without any 40-year obligation applying.
- If the composition has changed, both versions need to be kept. Each one documents a distinct period of employee exposure. Keep both for 40 years from the last date the original composition was in use.
- Date every version you archive. The period during which it was in use is what gives it value as an exposure record. An undated collection of old SDSs is very difficult to use if an HSE inspector or solicitor comes asking.
- Don't discard the old version on the day the new one arrives. Transfer it to your archive at the same time the new one goes into use.
Who Keeps What Across the Supply Chain
Your position in the supply chain shapes your specific obligations and the point at which they apply.
| Role | SDS Obligation | Retention Period |
|---|---|---|
| Employer (Chemical User) | Keep current SDS available while in use; archive on discontinuation | 40 years from date of last recorded use |
| Manufacturer | Prepare and maintain accurate SDSs; update within 3 months of new hazard data | Keep current; own employee records follow 40-year rule |
| Importer/Distributor | Provide current SDS to customers at point of sale; issue updates as they arise | Must supply updated SDS at each sale; internal employee records follow 40-year rule |
One point to note: sell an imported substance under your own brand and UK REACH treats you as the manufacturer. That brings with it the full responsibility for authoring the SDS and holding the underlying classification data.
Building a System That Handles Both Rules
Keeping SDS records well-organised across their full lifespan, from day-to-day use through a 40-year archive, takes some forethought. Current SDSs need to be close at hand for staff. Archived ones need secure, long-term storage away from daily use.
The detail most often missed is recording the last-use date the day a product comes out of service. Leave it too long and the date is gone. Without it, you can't show when the 40-year clock started. Your archive won't hold up if it's ever reviewed. For larger inventories, a dedicated SDS management system handles version tracking and last-use dates without manual effort. Cloud-backed storage also protects against losing decades of records to a single hardware failure.
Two further points to address early. If the business changes hands, all exposure records pass to the new owner. If it closes with nobody to receive them, they should be transferred to HSE. File formats change over time too, so build a review of your archived files into your schedule every few years. A document saved in 2001 may not be readable in 2031.
Final Thoughts
SDS compliance under COSHH has two distinct sides. The first is keeping a current SDS within reach for every substance in active use. The second is retaining records for 40 years after a substance was last used on site.
Begin by cross-referencing your current chemical inventory with your SDS files. For anything no longer in use, check that a last-use date is recorded and that the SDS is properly archived. Where a supplier updated the product's composition at any stage, you need both versions. Work through your list of discontinued substances this month and identify any without a confirmed last-use date. That's the most common gap. It tends to surface when a former employee makes a health claim years later.
Frequently Asked Questions
Does the 40-year rule apply to substances used only now and then?
Yes. It covers any substance employees were exposed to, regardless of how frequently it was used. Infrequent use still creates a record-keeping obligation.
Can you hold SDSs digitally to satisfy the 40-year requirement?
Yes. HSE accepts electronic records provided they can be retrieved without delay. Staff need access during their working hours, and HSE inspectors need access when they request it.
What if your supplier shuts down and you can't obtain old SDSs?
The obligation remains with you. Use the substitute record approach: document the substance name, where it was used, and the dates of use.
Do you need to keep the SDS for a product you received but never actually used?
If no employees were exposed to it, the exposure record requirement doesn't apply. The active-use obligation under COSHH Regulation 5 also doesn't apply if the product was never put into use.
How long must a safety data sheet be kept after an employee leaves?
The 40-year period is tied to the substance, not the individual. The clock runs from the last date of use regardless of when the employee left.
Zarif Ahmed
An engineer and safety writer by profession, focusing on chemical management, regulatory development, and the patterns that shape workplace practice over time.