Sikaflex® NP1, 1A & 15 LM: Updated Shelf Life Explained
When working with professional-grade sealants, shelf life is more than a date on a tube—it’s a key factor in performance, reliability, and job-site compliance.
Sika has officially announced an improvement to the shelf life of several widely used Sikaflex® polyurethane sealants. This update applies to both new production and qualifying existing inventory and is fully backed by manufacturer documentation.
Below, we explain what changed, how to check your product, and what it means for you.
Why Shelf Life Matters for Sealants
Moisture-curing polyurethane sealants are engineered for specific performance characteristics—elasticity, adhesion, and cure behavior. Over time, even unopened material can become:
- Harder to dispense
- Less flexible after cure
- Inconsistent in performance
That’s why manufacturer-approved shelf life guidance is critical. The recent update from Sika reflects improved formulation stability and validated testing—not assumptions or distributor estimates.
Official Shelf Life Improvements
Sika has confirmed improved shelf life for the following products:
- Sikaflex® NP1
- Sikaflex® 1A
- Sikaflex® 15 LM
New Standard Shelf Life (Effective Immediately)
- Cartridges: 15 months
- Sausages / Propaks: 18 months
These shelf lives now apply as the standard going forward.
What About Existing Inventory?
This update does not only apply to newly manufactured product. Certain inventory already in circulation is automatically covered under Sika’s extension guidelines.
Sikaflex® 1A & 15 LM – Transitional Rules
Starting August 25, 2025, product packaging will reflect updated “Best Used By” dates.
For product manufactured on or before August 24, 2025, Sika has approved the following automatic extensions:
Cartridges
- Printed “Best Used By” dates between June 15, 2025 and August 24, 2026
- Approved shelf life extends 3 months beyond the printed date
Sausages / Propaks
- Printed dates between March 15, 2025 and August 24, 2026
- Approved shelf life extends 6 months beyond the printed date
No relabeling or repackaging is required—these extensions are manufacturer-authorized.
How to Read Sikaflex® NP1 Dates
Sikaflex® NP1 uses Julian manufacturing dates rather than standard “Best By” dates. Understanding this format helps ensure proper use.
Example Julian Code
S9R 4180 E03
- 4 = Year (2024)
- 180 = 180th day of the year (June 28)
Approved Shelf Life for NP1
Based on the manufacture date:
- Cartridges manufactured after June 15, 2024
→ 15 months shelf life - Sausages / Propaks manufactured after March 15, 2024
→ 18 months shelf life
This method is consistent with Sika’s updated Product Data Sheets and official guidance.
What This Means for Contractors & Buyers
These updates provide real advantages on the job site and in inventory planning:
- Less product waste
- Greater flexibility for phased or long-term projects
- Improved confidence when verifying material compliance
- Manufacturer-backed assurance—not interpretation
When stored properly and used within approved shelf life, these products continue to meet Sika’s performance standards.
Need Help Verifying Shelf Life?
If you’re unsure how to read a date code or want help confirming whether a product is within its approved shelf life, our team is happy to assist.