This article explains what ZDHC MRSL and Chemicals to Zero (CtZ) certification levels mean, how they are determined for a product, and how to read them in your product portfolio.
01/ Introduction
ChemCheck products can carry two types of certification, both assigned by approved ZDHC Approved certification bodies:
- ZDHC MRSL (Manufacturing Restricted Substances List): measures conformance with the ZDHC MRSL, a list of hazardous chemicals that must not be used above specific limits.
- Chemicals to Zero (CtZ): a higher-ambition programme that recognises formulators working towards eliminating specific chemical classes entirely.
Both certifications are assigned independently by certification bodies and are displayed on your product in the portfolio and on the published product page.
02/ MRSL certification levels
| Level | What it means |
| Level 1 | The product meets the ZDHC MRSL at the foundational conformance level. |
| Level 2 | The product meets the ZDHC MRSL at the progressive conformance level. |
| Level 3 | The product meets the ZDHC MRSL at the aspirational conformance level. |
| Not Applicable | MRSL certification is not applicable to this product type. |
03/ Chemicals to Zero (CtZ) levels
The CtZ designation is selected by the certification body as part of the ZDHC MRSL certificate. The available CtZ levels depend on the ZDHC MRSL level of the certificate being issued:
| ZDHC MRSL level | Available CtZ levels |
| Level 1 | Foundational only (automatically assigned) |
| Level 2 or 3 | Foundational, Progressive, or Aspirational (CB selects, subject to their accreditation) |
| CtZ Level | What it means |
| Foundational | The minimum CTZ designation; assigned to all MRSL-certified products. |
| Progressive | The formulator has eliminated a broader set of priority chemical classes. |
| Aspirational | The highest level of Chemicals to Zero recognition. |
| Not Applicable | CtZ is not applicable to this product. |
04/ How the displayed level is determined
A product may be assigned to multiple certification bodies, and each CB may assign different certificate levels. The platform always displays the best (highest) level across all valid certifications.
For ZDHC MRSL: The platform reviews all active ZDHC MRSL certifications across all assigned CBs and displays the highest level achieved.
For CtZ: The same logic applies — the highest CtZ level across all active certifications from assigned CBs is shown.
Expiration date: The expiration date shown on the product corresponds to the active certification that determines the displayed level.
05/ Where to see certification levels
- Product portfolio table: ZDHC MRSL and CtZ levels are shown as columns for every product in your portfolio.
- Product detail page → Certificates tab: Shows all assigned CBs, their individual certification levels, assignment dates, and review status.
06/ Tips & Notes
Notes:
- A certification body must first be assigned to your product before they can issue any certificate. See How to assign certification bodies to your product.
- CtZ levels above Foundational require a Level 2 or Level 3 ZDHC MRSL certificate from the same CB. Progressive and Aspirational CtZ are not available for products certified only at Level 1.