Canada DSL search for chemicals and polymers before export
The Canada DSL is the existing-substance list. An unflagged entry needs no new-substance notice. Check by CAS number, then read an NDSL or blank result.
Canada DSL search before you ship
The Canada DSL (Domestic Substances List) is Canada's inventory of existing substances. A chemical or polymer with an unflagged entry on the DSL inventory can be made or imported without a new-substance notification.
Check by CAS number in Environment and Climate Change Canada's Substances Search, then check for Significant New Activity (SNAc) requirements. A substance on the NDSL, or on neither list, needs notification before the applicable quantity is exceeded, unless an exemption applies. CEPA section 81 sets these duties.
What the Canadian Domestic Substances List is
The DSL comes from section 66 of the Canadian Environmental Protection Act, 1999 (CEPA). A substance qualified if, between January 1, 1984 and December 31, 1986, it was made or imported at 100 kg or more in a calendar year, or it was in Canadian commerce, or it was used for commercial manufacturing in Canada. First published in May 1994 with about 23,000 substances, it now holds more than 28,000 and is amended about 12 times a year. On July 30, 2026, SOR/2026-168 added 656 Revised In Commerce List substances to Part 1.
The list has eight parts. Parts 1 and 2 cover chemicals and polymers listed by CAS Registry Number. Parts 3 and 4 cover confidential entries, listed by masked name and Confidential Accession Number (CAN). Parts 2 and 4 are the SNAc parts. Parts 5 to 8 cover living organisms, split the same way.
How to do a Canada DSL search
Environment and Climate Change Canada's free Substances Search covers the DSL, the NDSL, and SNAc orders and notices. You can search by identifier (CAS RN, CAN, Enzyme Commission number and others), by name, or browse a whole list.
- Get the CAS number for each component. Mixtures are not notified as a whole. Each new component is.
- Use the CAS number. A name search returns lookalikes, because DSL names follow CAS index style.
- Note which list the hit is on: DSL or NDSL.
- A DSL hit is not finished until you check SNAc. The New Substances Notification Regulations (NSNR) guidance says the search engine does not show flags. Check Part 2 or Part 4, and read the Canada Gazette order for that substance.
- A blank result does not prove the substance is unlisted. The tool's own disclaimer says a substance with no result "may still be implicated in certain lists or groups of substances."
Confidential entries are one reason a CAS search can miss a listing. CEPA s. 88 allows masked names, so a substance can sit on the DSL without its CAS number showing. Anyone who intends to make, import or use a substance can file a Confidential Search Request (previously called a "bona fide intent to manufacture or import"). The guidance gives a 15-day response period after receipt of complete documents. A fee applies.
Use the live tool, not an old download. The DSL is amended about 12 times a year, and a notified substance moves from the NDSL to the DSL once it is listed (s. 87), so a saved copy goes stale.
On the DSL with a SNAc flag
The published list marks SNAc entries with an S or S′ flag. Both mark an entry subject to SNAc requirements; the flag only tells you whether SNAc applied before the substance was added (S) or not (S′). Read the entry's definition of a significant new activity, including its thresholds and exclusions. Under CEPA s. 81(3), you cannot start that activity until the required information is filed and the assessment period expires.
Check the deadline in the applicable order. SOR/2026-43 requires 90 days' advance information for the activities it specifies, not for every flagged DSL substance. If you transfer a flagged substance, s. 87.1(1) requires you to tell the recipient about the obligation.
If it's on the NDSL instead
The Non-domestic Substances List holds over 50,000 chemicals and polymers not used commercially in Canada above trigger quantities. It is updated yearly with substances that have been on the US EPA's TSCA Inventory for at least one year. Confidential TSCA entries are not added automatically.
This is the step US suppliers most often get wrong. An NDSL listing is not Canadian clearance: the substance is still new under CEPA s. 81(1). The listing only raises the triggers and cuts the data. Under the New Substances Notification Regulations (Chemicals and Polymers) (NSNR), an NDSL chemical has no notice at 100 kg.
If it's on neither list
For ordinary chemicals, NSNR sections 7 and 8 set the thresholds below. File in advance, and let the assessment period expire, before the quantity exceeds a threshold. Section 4 exempts the substance until that first quantity is exceeded. Do not use the table for research and development chemicals, contained site-limited intermediates or contained export-only chemicals. Those follow section 5: Schedule 1 at least 30 days before exceeding 1,000 kg a year.
| Before exceeding annual quantity in Canada | Chemical not on NDSL | Chemical on NDSL |
|---|---|---|
| 100 kg | Schedule 4, 5 days before | no notice |
| 1,000 kg | Schedule 5, 60 days before | Schedule 4, 30 days before |
| 10,000 kg | Schedule 6, 75 days before | Schedule 5, 60 days before |
| 50,000 kg | no further chemical tier | extra data, 75 days before, only if a release or exposure test is met |
That 50,000 kg step applies only if aquatic release exceeds 3 kg per day per site, or the public may be significantly exposed through a product.
Polymers use NSNR sections 6 and 10 to 12, not the table. The usual first step is Schedule 9, 30 days before exceeding 1,000 kg a year. At 10,000 kg, Schedule 10 or 11 can follow, with 60 days' notice. Reduced regulatory requirement polymers are exempt from the section 12 (Schedule 11) requirement. Research and development polymers, contained site-limited intermediates and contained export-only polymers follow section 6: Schedule 3 at least 30 days before 10,000 kg. Biochemicals and biopolymers also need Schedule 2.
Fees apply, scaled to Canadian sales under the New Substances Fees Regulations.
Some things fall outside notification entirely. CEPA s. 81(6) excludes substances for uses regulated under the Pest Control Products Act, Fertilizers Act or Feeds Act, along with impurities, contaminants, partially unreacted materials and incidental reaction products. Transient intermediates are out only if they are not isolated and are not likely to be released. NSNR section 3(2) excludes substances in transit through Canada. Food, drug and cosmetic ingredients are not exempt merely because of their use, as the guidance explains.
Who files the New Substances Notification
The notifier is the person who makes or imports the substance in Canada. For an exporter, that usually means the Canadian importer files the New Substances Notification (NSN). A foreign supplier can notify only through a person resident in Canada: SOR/2005-247 s. 14(3) requires a non-resident notifier to name a Canadian resident authorized to act for it. Records must be kept in Canada for five years (s. 13). For a cited answer on a specific substance, you can ask RegAffairs AI, which links each claim to its official source.