SAF Haze and PSI: Training and IPPT Guide

There is no single public PSI number that means "no NS".

MINDEF says SAF training continues as normal when PSI is 100 or below. When PSI exceeds 100, the SAF reduces physical and outdoor training according to its own PSI-Activity Guidelines. The actual response can therefore be an adjusted activity, lower intensity, an indoor move, or a cancellation—not an automatic day off.

For a booked NSman IPPT or NS FIT session, the public rule is more specific: MINDEF says a session will be conducted indoors or cancelled if PSI reaches hazardous levels, and a cancelled session will be notified by SMS.

This guide is unofficial. Live instructions from your unit, conducting body, commanders, trainers, medical staff, OneNS, and MINDEF override it.

Quick version

• PSI of 100 or below: MINDEF says SAF training continues as normal.
• PSI above 100: the SAF reduces physical and outdoor training; this does not mean all training or book-in is cancelled.
• SAF also considers the 24-hour PSI forecast and 1-hour PM2.5 readings when calibrating the level and intensity of training and outdoor activities.
• Booked NSman IPPT or NS FIT: at hazardous PSI, MINDEF says the session will be indoors or cancelled; wait for the official SMS instead of assuming.
• If you feel unwell, inform your commander or instructor immediately and use the report-sick route. A reading on your phone is not a medical assessment.

The Number Does Not Decide Everything​

The common question is: "At what PSI does NS stop?"

That framing hides three different decisions:

1. whether a particular SAF activity continues unchanged;
2. whether physical or outdoor training is reduced, moved, or cancelled; and
3. whether a booked NSman IPPT or NS FIT session is cancelled.

The public rules are not identical for all three.

MINDEF's current haze FAQ states that SAF training continues as normal at PSI 100 or below. When PSI exceeds 100, the SAF reduces physical and outdoor training accordingly. The same FAQ says the internal guidelines account for a serviceman's medical fitness and the nature of the training activity.

That is why two activities can have different outcomes during the same haze period. A lower-intensity or indoor conduct may continue while another outdoor activity is reduced or moved. Public guidance does not give you a universal cancellation table for every BMT, unit, course, field, guard-duty, or ICT activity.

What The SAF Checks During Haze​

MINDEF's February 2026 media reply says the SAF closely monitors air quality and uses both:

• the 24-hour PSI forecast; and
• the 1-hour PM2.5 concentration level.

The SAF then calibrates the level and intensity of training and outdoor activities, with precautionary measures for servicemen's health and safety.

This two-reading approach matters because PSI and 1-hour PM2.5 answer different questions.

NEA says the 24-hour PSI is based on a rolling 24-hour average across six pollutants. Its forecast and health advisory are useful for planning activities over the next day or for longer exposure. The 1-hour PM2.5 reading reflects more immediate fine-particle conditions and can move more quickly during a haze episode.

Do not replace either one with a random international air-quality app and assume it controls SAF activity. Check the official NEA or haze.gov.sg reading for context, then follow the live SAF instruction for the conduct.

The Public SAF Haze Thresholds​

Here is the narrowest accurate reading of the published rules.

Official public state	What it means
PSI 100 or below	MINDEF says SAF training continues as normal.
PSI above 100	The SAF reduces physical and outdoor training according to its PSI-Activity Guidelines. This is not a promise that all activity stops.
Hazardous PSI for booked NSman IPPT or NS FIT	MINDEF says the session will be conducted indoors or cancelled. A cancellation is notified by SMS.

NEA classifies a 24-hour PSI above 300 as Hazardous. Keep the terms straight: "Unhealthy" begins above 100, while "Hazardous" is above 300.

The current public MINDEF FAQ does not publish the SAF's full internal activity matrix. It does not say that every activity is automatically cancelled at one number, nor that servicemen can self-release, skip book-in, or leave camp based on the public reading.

If You Are An NSF Or In SAF Training​

Use a three-part check instead of asking whether there is "no NS".

1. Check the live official instruction​

Confirm what your commander, instructor, conducting body, or duty channel has said about the specific activity. The answer may be normal conduct, reduced physical load, shorter exposure, a move indoors, a timing change, or cancellation.

Do not treat another company's outcome, a Reddit comment, or an old 2015 experience as your instruction. Haze conditions, activity type, medical fitness, and the current safety plan may differ.

2. Make your health status visible​

CMPB says to report sick if you are unwell and to inform your commander immediately if you or your buddy do not feel well. It also says to declare a medical excuse before a strenuous activity.

Use specific facts:

• "I am wheezing and it is getting worse."
• "My chest feels tight."
• "I feel giddy and cannot continue."
• "My eyes and throat are irritated and I am not feeling well."
• "I have a current medical excuse or condition that may affect this activity."

Do not diagnose yourself from PSI alone. Do not hide symptoms until the activity ends. The practical safety action is to report what is happening and let the official medical or command route assess it.

3. Keep book-in and training cancellation separate​

An outdoor conduct being reduced or cancelled does not automatically cancel book-in, duty, indoor activity, or every item on the programme.

Unless you receive a direct instruction, follow the existing reporting order and ask through the named unit channel if the plan is unclear. A haze reading is not self-authorisation for absence.

If You Have A Booked IPPT Or NS FIT Session​

The public MINDEF answer for NSman IPPT and NS FIT is simpler but still does not support guessing.

If PSI reaches hazardous levels, the session will be:

• conducted indoors; or
• cancelled.

MINDEF says you will receive an SMS if it is cancelled. Until that notification or another official instruction arrives, do not assume the booking has disappeared.

Before leaving home:

1. check your booking and contact details in the official system;
2. check for the cancellation SMS;
3. check any official OneNS or MINDEF notice tied to the session; and
4. if the message is unclear or missing, contact the official route rather than relying on a crowd-sourced threshold.

If a session is cancelled or does not update correctly, preserve the booking, notification, and OneNS status. Then use the IPPT cancelled or missing-record guide. If the replacement options are tight near the end of your window, use the no-IPPT-slots guide early rather than waiting for the deadline.

A Two-Minute Haze Check​

Use this before an outdoor training day or booked fitness session:

• Plan ahead: check the official 24-hour PSI forecast and haze advisory.
• Check the immediate condition: look at the official 1-hour PM2.5 reading for your region.
• Check the activity owner: confirm the unit, course, FCC, OneNS, or SMS instruction for the exact conduct.
• Check yourself: report symptoms, illness, or a relevant medical status before strenuous activity.
• Keep the instruction: save the cancellation SMS or official message if it changes a booking or reporting plan.

The readings inform the decision. The activity owner communicates the decision. Your health information still has to reach the people who can act on it.

What Not To Infer​

• "PSI crossed 100, so the whole day is cancelled." No. MINDEF says physical and outdoor training is reduced above 100; it does not publish a universal no-NS rule.
• "The sky looks clear, so the reading does not matter." No. Use the official readings and instructions, not visibility alone.
• "The 24-hour PSI looks moderate, so a current PM2.5 spike is irrelevant." No. MINDEF's 2026 statement says both the 24-hour PSI forecast and 1-hour PM2.5 are used.
• "My IPPT must be cancelled because it is hazy." Not necessarily. The public rule allows indoor conduct or cancellation at hazardous levels; wait for the official notice.
• "I can skip book-in because outdoor PT cannot happen." No. A training adjustment is not self-authorisation for absence.
• "Everyone has the same haze risk." No. Official guidance accounts for medical fitness, health status, exposure time, and activity intensity.

Where Public Guidance Stops​

Public sources do not expose the complete SAF Medical Directives, Training Safety Regulations, local PSI-Activity matrix, or the live decision for your conduct.

They also do not let an unofficial guide decide:

• whether your specific activity will move indoors;
• whether your training programme or ICT changes;
• whether your medical condition changes your participation;
• whether a booked session has officially been cancelled; or
• whether your reporting time changes.

Use the public thresholds to understand the framework. Use the live official instruction to act.

Frequently Asked Questions

At what PSI is SAF training cancelled?

There is no universal public cancellation number for all SAF activities. MINDEF says training continues as normal at PSI 100 or below and physical or outdoor training is reduced above 100. The actual adjustment depends on the activity, medical fitness, live conditions, and official safety plan.

Will haze cancel my NSman IPPT or NS FIT session?

MINDEF says IPPT and NS FIT will be conducted indoors or cancelled when PSI reaches hazardous levels. If the session is cancelled, you will receive an SMS. Check the official booking and notice instead of assuming from the reading alone.

Should I check PSI or 1-hour PM2.5 before NS training?

Both are relevant. MINDEF says SAF calibrates activities using the 24-hour PSI forecast and 1-hour PM2.5 levels. NEA uses 24-hour PSI for longer-range planning and 1-hour PM2.5 for immediate conditions. The live SAF instruction still controls the activity.

Official References​

• MINDEF: How haze affects SAF training and physical activities
• MINDEF: 2026 SAF haze measures for servicemen safety
• MINDEF AskGov: Haze on an IPPT or NS FIT day
• NEA: Using 1-hour PM2.5 and 24-hour PSI
• CMPB: SAF training safety checklist
• Haze.gov.sg: Official live air-quality information

Bottom Line​

There is no public "PSI equals no NS" rule. At 100 or below, SAF training continues as normal; above 100, physical and outdoor training is reduced. Booked NSman IPPT or NS FIT sessions may move indoors or be cancelled at hazardous levels, with cancellation sent by SMS. Check official readings, follow the live instruction, and report symptoms early.

Related Reads​

• NS Heat Safety for Hot Weather
• NS Training Safety: When To Sound Out
• IPPT Cancelled or Missing: Record Checks
• No IPPT Slots Before Your Window Ends
• Commander Start Here