MSC.581(110) Enclosed Space Compliance
IMO Resolution MSC.581(110) introduces enhanced safety measures for enclosed space entry, including defined carbon dioxide limits and strengthened atmospheric testing procedures.
Are Your Enclosed Space Monitors Compliant?
From December 2025, vessels must ensure compliance with updated atmospheric testing requirements under SOLAS Chapter III and associated guidance.
As a specialist marine safety distributor, we support shipowners and managers in selecting compliant atmospheric testing and personal detection equipment from leading global manufacturers.
WHAT HAS CHANGED UNDER MSC.581(110)?
The International Maritime Organization adopted IMO Resolution MSC.581(110) in June 2025, replacing IMO Resolution A.1050(27).
The resolution strengthens enclosed space entry procedures and updates the guidance to reflect ongoing casualty investigations.
Key updates include:
| Requirement | Previous | New Standard |
|---|---|---|
| CO₂ Monitoring | Not specified | Mandatory < 0.5% (5,000 ppm) |
| O₂ Levels | ≥ 19.5–20.9% | ≥ 20.9% required |
| Personal Detectors | Practice-based | Recommended for all entrants |
| Permit Duration | Variable | Max 8 hours |
| Single Entry | Often allowed | Explicitly prohibited |
CO₂ monitoring is now a critical compliance requirement. Most legacy multi-gas detectors do not measure CO₂.
Fast response | Technical guidance | UK-wide delivery
Prefer email? Contact fiona@ribble-enviro.co.uk to request availability or hire quotations.
FREQUENTLY ASKED QUESTIONS
Got a query about hiring gas detection equipment? Below, we've answered some of the most common questions we receive about hiring from our fleet of gas detection instruments, and servicing and maintenance during the hire period.
If you can’t find what you’re looking for, speak to our hire specialists and we’ll guide you straight to the safest, most cost-effective solution.
Our “hot-swap” service ensures minimal disruption. If recalibration or servicing is required, we’ll replace your unit immediately and handle all logistics to keep your project running smoothly.
Absolutely. You can extend your hire at any time — simply contact our hire team, and we’ll update your agreement and continue support without interruption.
Yes. Every Ribble Enviro hire instrument is supplied fully tested, certified, and accompanied by an up-to-date calibration certificate to ensure compliance with safety and environmental standards.
Yes. Our experienced specialists can help identify the right gas detector for your application — whether that’s confined space entry, area monitoring, or VOC detection. You’ll receive expert guidance before, during, and after hire.
Yes. If preferred, you can arrange to collect equipment directly from our depot. Simply let our hire team know when placing your order, and we’ll prepare your instruments for collection at your convenience.
Yes. We provide emergency and out-of-hours support for critical systems where downtime poses safety or operational risks. Our rapid response team ensures your fixed gas detection network remains safe and compliant, 24/7.
FINAL CALL TO ACTION
Prefer email? Contact fiona@ribble-enviro.co.uk to request availability or hire quotations.