WORKPLACE SAFETY
MOM’s New Hourly PM2.5 Rule Means Haze Signage Can’t Wait Until Tomorrow
On 20 October 2026, the Ministry of Manpower issued new guidance that changes how employers are expected to manage haze risk for outdoor workers. Until now, the standard approach was to check the next day’s PSI forecast and plan accordingly. The new guidance adds a second, faster-moving layer: 1-hour PM2.5 readings, checked during the workday itself, with specific actions attached to specific numbers. For any site that relies on a sign posted once at the morning briefing, that’s a problem — because under this guidance, the right instruction for a worker at 9am may no longer be the right one by 1pm.
Why MOM Added a Same-Day Layer
The existing PSI forecast tells employers what tomorrow is likely to look like, which is useful for deciding whether to reschedule a job in advance. What it can’t do is tell a supervisor what’s happening right now, at 2pm, when PM2.5 levels can shift within hours as haze drifts in from regional fires. MOM’s new guidance closes that gap: employers are now expected to check 1-hour PM2.5 readings (available at haze.gov.sg) throughout the day and adjust outdoor work in real time, not just the night before.
The Four Bands, and What Each One Actually Requires
MOM’s guidance sets out four PM2.5 bands, each with a different required response:
- Band 1 — Normal (0–55 µg/m³): Outdoor work continues normally; employers monitor the situation.
- Band 2 — Elevated (56–150 µg/m³): Healthy workers reduce strenuous outdoor work; vulnerable workers avoid it. Employers are expected to use mechanical aids, job rotation, indoor rest breaks and hydration as mitigation.
- Band 3 — High (151–250 µg/m³): Strenuous outdoor work should be avoided for healthy workers and prohibited for vulnerable workers unless it genuinely can’t be deferred — in which case masks are required.
- Band 4 — Very High (251 µg/m³ and above): Outdoor work is minimised for healthy workers and prohibited for vulnerable workers (defined by MOM as the elderly, pregnant employees, and those with chronic heart or lung conditions). Where work can’t be avoided, MOM requires masks or respirators, hourly 10–15 minute indoor rest breaks, and a risk assessment that accounts for reduced visibility — specifically flagging crane lifting operations.
The jump from Band 2 to Band 3 is the one most sites will feel first: it’s the point where “reduce” becomes “avoid,” and where a mask requirement kicks in for the first time.
Why a Static Sign No Longer Covers This
A haze advisory poster at the gate, checked once in the morning, answers the question “what should we do today?” It can’t answer “what band are we in right now?” — and under MOM’s new guidance, that’s the question that actually determines whether strenuous outdoor work is permitted at that moment. Sites that already keep haze and air-quality warning signage posted at entry points and rest areas have the right foundation — what changes is that the information on it needs to be checked and updated through the day, not set once. A simple, low-cost fix many sites are adopting: a dry-erase or slot-in panel next to the fixed warning sign where the current band is updated each time someone checks haze.gov.sg, so every worker walking past the gate can see at a glance whether they’re in Band 2 or Band 4 — not just that haze policy exists somewhere in a folder.
Pairing that with prohibition signage at the point where outdoor work is restricted under Band 3 or 4, and keeping the mask supply MOM now expects — a minimum one-week stock under haze-related Business Continuity Plans — next to clearly marked signage rather than a back-office store, closes the gap between what the policy says and what a worker standing outside at 1pm actually knows.
Haze season doesn’t wait for a morning briefing, and under MOM’s new guidance, neither can your signage. Browse our full range of SS 508-compliant safety signs at safetysigns.sg.
Author: safetysigns.sg Team
Date: 23 October 2026