Haze and outdoor work: what Singapore employers should do at each hourly PM2.5 band

During haze, air quality can change by the hour. On 20 October 2026, the Ministry of Manpower (MOM) issued new guidance on adjusting outdoor work during the day using 1-hour PM2.5 readings, alongside its existing PSI forecast guidance.

This guide covers what each PM2.5 band asks of you, what your haze plan needs, masks, vulnerable workers and a checklist for this week. Every rule links to MOM, the National Environment Agency (NEA) or the Workplace Safety and Health (WSH) Council.

What MOM's new guidance asks

MOM asks employers to use two readings for two jobs (MOM: press release, 20 October 2026):

• The PSI forecast, to plan tomorrow, including which activities to reduce or reschedule.
• The 1-hour PM2.5 reading, to adjust today as air quality changes.

The core message: progressively reduce outdoor work as the 1-hour PM2.5 readings rise. NEA notes the hourly reading can be volatile, while the PSI forecast is steadier. (NEA: air pollution FAQs)

Is it a requirement or a guideline?

MOM's haze measures are guidelines, written as what employers "should" do, and MOM says they are "not meant to be prescriptive". (MOM: haze guidelines and advisory for work)

But the duty behind them is law. Under the WSH Act, employers must protect their employees' safety and health at work. MOM says failing to adequately mitigate haze risks, taking reference from the guidelines, may lead to enforcement action under the Act, including stop work orders and composition fines. (MOM: haze FAQs) MOM's guidelines also say it is the duty of employers to provide suitable masks, such as N95 masks, where warranted. (MOM: guidelines for employers on protecting employees from haze) In short: the bands are guidance, but you are expected to assess the risk and act on it.

Who it applies to

The guidance is for employers with outdoor workers. MOM defines outdoor work here as "work that is carried out outside buildings regularly or most of the time". (MOM: guidelines) That's worded differently from the heat stress definition, so check your roles against both.

Where to read the 1-hour PM2.5 band

NEA publishes 1-hour PM2.5 readings for five regions: North, South, East, West and Central. Use your site's region, or the closest one, so crews across the island may be in different bands at once. Readings are on haze.gov.sg, the NEA website and the myENV app. (NEA: air pollution FAQs)

What to do at each PM2.5 band

This is MOM's Table B, in MOM's words. Vulnerable employees are the elderly, pregnant women and those with chronic heart or lung diseases. (MOM: guidelines, Table B; MOM: press release annex)

In MOM's terms, reduce means do less, minimise means do as little as possible, avoid means do not do, and prohibit means must not allow. At Band 4, risk assessments should also account for reduced visibility, especially for tower and mobile crane lifts.

Planning tomorrow with the PSI forecast

MOM's Table A does the same for the next day: from a PSI forecast of 101 (Unhealthy), reduce prolonged or strenuous outdoor work, with tighter limits for vulnerable employees. For prolonged outdoor work at a PSI forecast above 400, MOM says to consider respirators with a higher protection factor, such as full face respirators, as an N95 mask may not be enough. (MOM: guidelines, Table A)

What your haze plan should include

MOM reminds employers to review their haze management plans, including (MOM: press release, 20 October 2026):

1. identifying workers who are more susceptible to the effects of haze
2. deciding which outdoor work activities should be reduced or rescheduled
3. setting criteria for restricting outdoor work as haze conditions worsen
4. keeping at least a one-week supply of masks as part of your haze-related business continuity plan, if you have employees who must work outdoors

MOM's guidelines add mask fit testing for employees who still work outdoors, better air cleaning devices, and a haze communication system that updates staff and lets them report ill effects. (MOM: guidelines) The WSH Council's adverse weather guidelines also list monitoring workers' health. The tripartite advisory from MOM, NTUC and SNEF asks you to brief employees on your business continuity plan and engage them and any union early. (MOM: tripartite advisory on haze-related workplace measures)

N95 masks: what MOM expects

• The right mask filters out about 95% of very fine particles, such as an N95 or equivalent.
• Fit-test, train and supervise wearers, keep enough stock, and change masks when soiled, damaged or hard to breathe through.
• Masks make breathing harder. Allow regular breaks, a slower pace and water. If a worker struggles to breathe in a mask outdoors, redeploy them indoors.
• Respirator wearers need a medical assessment of their fitness to use one. MOM points to Singapore Standard SS 548:2022. (MOM: guidelines; MOM: haze FAQs)

Vulnerable workers, leave and pay

Vulnerable employees should consult their doctors on mask use, and MOM strongly encourages flexible work arrangements such as staggered hours, especially for them. If a worker is unwell and wants to rest at home, be flexible with leave; if their paid leave is used up, MOM suggests advance leave or other arrangements, without deducting wages. If you suspend operations short-term because of haze, bear the cost and don't deduct pay or leave; for longer suspensions, agree arrangements with your union and employees. (MOM: haze FAQs; MOM: tripartite advisory)

If an employee falls ill or is injured from working outdoors in haze, notify MOM through WSH Incident Reporting. They may be eligible for work injury compensation. (MOM: haze FAQs)

Heat stress rules from 1 December 2026: what Singapore employers of outdoor workers must have in placeFrom 1 Dec 2026, four more heat stress measures become mandatory for outdoor work in Singapore. What MOM requires at each WBGT level, and a checklist.cova.sg/resources/sg-heat-stress-guide

What to do this week: a checklist

If your crews also work in the heat, run this alongside your heat stress checks.

• List who works outdoors, by role, site and route, and each one's NEA region.
• Identify vulnerable workers. Treat this as health information and share only what supervisors need.
• Write your band rules down: per site, which tasks change at Bands 2, 3 and 4, for healthy and vulnerable workers, and who decides.
• Name who checks the readings: a supervisor per site for the hourly PM2.5 band, and someone for the PSI forecast each day.
• Count your masks. Keep at least a week's supply of N95 masks, arrange fit testing, and brief workers on using them. Record who attended, as you would for any safety training.
• Plan indoor rest for Band 4, and check crane and lifting plans for poor visibility.
• Tell your staff the plan, how updates will reach them and how to report symptoms, and agree leave and pay arrangements.
• Keep a record. MOM doesn't prescribe a log, but noting the band, the work changed and the masks issued shows what you did.

How Cova helps

Cova is HR software for Singapore SMEs. Here's how it supports the people side of the checklist, depending on the modules you choose.

Mask and haze briefings on record. HR can add the company's own courses, such as an in-house briefing on wearing N95 masks. Managers can book a course for a direct report, and HR can book for anyone. Add the Training master list, and every course booking and certificate sits in one list, with one row per person per course and the class dates.

Sign-offs in one inbox. Training approvals sit in the same Approvals inbox as leave and form requests, and a request waiting more than 3 days turns red. Approvals works on a phone too, so supervisors can decide from site.

Daily haze checks and mask logs, set up for you. Want a daily haze-check form for supervisors, with the 1-hour PM2.5 band for the site's region, the work reduced and the indoor rest breaks given? Yes, we build and set this up for your team. HR can already build its own forms in Cova, with short text, multiple choice and file upload questions, and staff can fill them in on a phone. Want an N95 mask issue log with a running count against your one-week supply? Yes, we build and set this up for your team.

The steps removed: no chasing who's booked on a briefing, no approvals lost in chat threads, and no spreadsheet of who's been briefed.

Ask the Cova team for a quote for your headcount and the modules you need.

Approval workflows for Singapore SMEs: leave, training and onboarding without WhatsAppWhy chat approvals fail, what a good approval flow needs, and how to apply it to leave, training and onboarding.cova.sg/resources/sg-approval-workflows-smes

Frequently asked questions

This guide is general information, not legal advice. Guidance was checked against the MOM, NEA, haze.gov.sg and WSH Council websites on 22 October 2026. Always check the linked pages for the latest position.

Sources

• MOM, Additional guidance for employers on use of 1-hour PM2.5 readings to protect outdoor workers during haze (20 October 2026)
• MOM, Haze guidelines and advisory for work
• MOM, Guidelines for employers on protecting employees from the effect of haze
• MOM, Tripartite advisory to employers on haze-related workplace measures
• MOM, WSH Incident Reporting
• NEA, Air pollution FAQs
• NEA, haze.gov.sg
• WSH Council, WSH Guidelines: Preparing for Adverse Weather (2025)