The transition to ZDHC MRSL V4.0 begins on 1 November 2026 and the supply chain implementation period ends on 1 June 2028.
The transition allows chemical formulators to recertify their formulations, while suppliers progressively work to identify and phase-out non-conformant substances.
Key milestones:
| Date | Milestone |
| 1 November 2026 | Transition begins |
| 1 February 2027 | Formulation recertification begins |
| 1 November 2027 | Formulation recertification period ends |
| 1 June 2028 | Supply chain implementation period ends |