Southeast Asia’s outdoor workers face heat and haze with no legal shield

Malaysia’s occupational heat safety guidelines remain advisory and voluntary, even as Southeast Asia’s temperatures rise and the Asian Development Bank warns that protections for outdoor workers are weak or poorly enforced.
The 2016 guidelines from the Department of Occupational Safety and Health recommend risk assessments and rest breaks, but employers are not legally required to follow them.

Meanwhile, transboundary haze from Indonesian fires forced Sarawak to cancel public outdoor events in late August, and schools closed when air pollution hit designated thresholds.
Children and students received protective orders while most outdoor workers still lack binding safeguards.

Chung Kee Wa, a 68‑year‑old smallholder in southern Malaysia, reorganises his oil palm work around the sun.
“We try our best to avoid going to the plantation around noon,” he says, keeping to the early morning and evening.
An owner‑operator, he can carry extra water and decide when to stop.
Most of Southeast Asia’s outdoor workforce cannot.

Across construction sites, agricultural plantations and delivery platforms, the schedules that govern labour are set by employers or output demands, not by the heat index.
An Asian Development Bank assessment released in June found that many cities in the region have not carried out adequate heat‑risk evaluations, and that rules meant to shield outdoor workers from extreme heat are either weak or poorly enforced.
The gap between a warming climate and a regulatory framework that still relies on voluntary compliance is no longer an oversight.
It has become a daily health calculation that workers are forced to make on their own.

A regulatory gap the heat keeps widening

In 2016, Malaysia’s Department of Occupational Safety and Health (DOSH) issued guidelines on heat‑stress management.
They recommend that employers assess risks, provide drinking water, shade and staggered hours.
What they do not do is create a legal duty.
Compliance is voluntary — a fact that labour activists have long criticised.

Leong Choon Heng, a human‑rights and labour advocate, notes that the absence of statutory force leaves workers unprotected.
“Because they are advisory, compliance remains entirely voluntary,” he said, explaining why enforcement at worksites is minimal.
The Occupational Safety and Health Act 1994 does impose a general obligation on employers to ensure worker welfare, and inspectors can levy fines of up to RM500,000 or two‑year prison terms if a breach is proven.
But without a binding heat‑specific threshold, a prosecution depends on demonstrating that an employer failed its broad duty during a heat event — a high bar that is rarely met.

The rules that exist are splintered by sector.
When Air Pollutant Index (API) readings exceed designated thresholds, schools suspend outdoor activities above 100 and close above 200, per binding directives from Malaysia’s Ministry of Education.
Yet no parallel mandate requires a construction foreman to halt work or a logistics firm to pull its riders off the road when the same air turns toxic.

Dr Kho Sze Shyang, a respiratory physician at Borneo Medical Centre in Kuching, advises that properly fitted N95 respirators offer the most reliable personal protection during severe haze.
He stresses, however, that individual masking cannot be the only defence — governments must issue directives to stop outdoor work when air quality becomes too hazardous.
Indonesia’s Ministry of Manpower has a more detailed framework: Permenaker No. 5/2018 sets quantitative heat‑exposure limits using the Indonesian heat stress index (ISBB) and requires employers to adjust work–rest cycles, provide engineering controls and monitor workers.
But oversight concentrates on formal, factory‑based employment; the palm‑oil smallholder and the app‑based delivery rider fall largely outside its reach.

From voluntary to binding — a decision that is overdue

Whether Malaysia will upgrade its advisory guidance is no longer a technical debate.
The Asian Development Bank has warned that heat is becoming a major development drag, cutting labour output, stressing healthcare systems, and demanding stronger governance.
Internal discussions on converting the 2016 guidelines into mandatory rules have been reported amid recent climate warnings, according to officials familiar with the deliberations.
If draft regulations with clear work‑rest cycles or temperature triggers emerge in the coming months, it would signal a shift toward enforceable protection.
If not, unions and rights groups will likely escalate their campaign against what they describe as a legal vacuum.

The economics reinforce the urgency.
Air‑quality studies coordinated with the ADB estimate that more than 85% of Southeast Asia’s population is exposed to unhealthy particulate levels, contributing to around 335,000 premature deaths annually.
In 2025–2026, average urban PM2.5 concentrations in Indonesian cities reached around 30 µg/m³ and in Vietnamese cities roughly 29.7 µg/m³ — approximately six times the WHO’s annual guideline of 5 µg/m³.
For outdoor workers breathing that air during a haze episode, the exposure is not a statistical abstraction; it is a direct respiratory load.

Western governments, meanwhile, are shaping outcomes through supply‑chain regulation rather than bilateral aid for worker safety.
The EU’s Corporate Sustainability Due Diligence Directive and its deforestation rules will require large European companies to identify and address human‑rights and environmental harms throughout their chains by the late 2020s, capturing plantation and logistics hubs in Malaysia and Indonesia.
This creates a potential enforcement path: plantation companies could face pressure to tighten heat and haze safeguards if failure to do so threatens access to European markets.
The mechanism is contractual — codes of conduct and audit requirements that increasingly reference occupational conditions — rather than regulatory, and implementation will take years to arrive.

The question for the region’s labour departments, then, is whether they will act before market pressures intensify.
Severe haze episodes have recurred in recent years, driven by seasonal fire patterns in Indonesian peatlands.
That gives regulators time to turn guidelines into law, or to accept that the protection gap will persist — and that the cost will keep falling on the workers whose jobs cannot wait for the air to clear.

Beyond the headline

The bigger picture

This story sits at the intersection of two structural shifts: Southeast Asia’s rising climate exposure and the persistence of informal, lightly regulated labour. As temperatures and haze episodes intensify, the same plantations, construction sites and logistics corridors that anchor global supply chains are staffed by workers whose protections depend more on employer discretion than legal triggers. Weak enforcement of both air-quality and occupational safety rules turns climate stress into a predictable drag on productivity and public health, rather than an exceptional shock.

The response gap

Authorities have tools — emergency declarations, school-closure thresholds and general safety duties under occupational law — but the gap lies in translating them into binding, worker-centred rules. Heat and haze responses often focus on episodic crises, like Sarawak’s API spike, while day-to-day protections for delivery riders, smallholders and construction crews remain voluntary. Until regulations define when work must pause and who bears the cost, outdoor workers will keep choosing between income and breathing easier.

The reach

One less visible actor shaping outcomes is the large Western buyer applying new EU due diligence standards to Southeast Asian suppliers. Their mechanism is contractual: codes of conduct and audit requirements that increasingly reference heat stress, air quality and labour conditions alongside deforestation. The implication is that plantation companies and logistics operators in places like Johor and Riau may tighten worker safeguards not primarily because local law requires it, but because failing to do so threatens export access to European markets and, ultimately, revenue.

Four fronts where the rules are being tested

With regulatory debates now out in the open, four groups face practical choices in the months ahead.

• Western procurement manager for Southeast Asian agricultural commodities

  You need to assess whether your direct suppliers have documented heat and haze mitigation plans — not just generic safety policies. Request evidence that outdoor workers receive rest breaks, hydration and, during haze, properly fitted N95 respirators. Monitor the EU’s Corporate Sustainability Due Diligence Directive implementation timeline on the European Commission’s company law pages; a supplier that cannot demonstrate worker safeguards by the late 2020s will become a compliance liability.

• Western investor with exposure to Southeast Asian industrial or agricultural sectors

  Evaluate whether portfolio companies have conducted heat‑risk assessments and are tracking worker illness or lost productivity data. Engage management on the timeline for updating safety protocols, particularly in Malaysia where DOSH’s deliberations over mandatory rules could alter legal risk. A firm that relies entirely on voluntary guidelines today may face rising reputational and regulatory costs if binding standards arrive without warning.

• Western parent of a university student in Malaysia

  During the July–October dry season, check the Malaysian Department of Environment’s hourly API readings for the state where your child is studying. School closures become mandatory when API exceeds 200; outdoor activities are suspended above 100. Supply your child with a supply of N95 masks and advice to limit outdoor exposure when the index rises, because campus routines may not adjust as quickly as official school guidelines.

• European tour operator with Southeast Asia packages

  Incorporate real‑time API monitoring into your operations; the Sarawak government cancelled Independence Day events when air quality deteriorated, and further restrictions are possible. Develop itinerary contingency plans for days when outdoor activities are unsafe, and communicate to clients that heat and haze are seasonal features, not rare surprises. Travel insurance that covers itinerary disruption from hazardous air quality is worth recommending explicitly.

Explainer

DOSH

The Department of Occupational Safety and Health is the Malaysian government agency responsible for enforcing workplace safety laws. Operating under the Ministry of Human Resources, it issues guidelines and conducts inspections under the Occupational Safety and Health Act 1994. Its 2016 heat‑stress guidelines remain advisory, not legally binding, which has become a central point of contention as heat risks rise.

Air Pollutant Index (API)

A standardized scale used in Malaysia to report daily air quality, analogous to the Air Quality Index in the United States. Readings between 0 and 50 are considered good; from 101 to 200, unhealthy for sensitive groups; and above 200, very unhealthy. Malaysia’s Education Ministry mandates school outdoor-activity suspension at API above 100 and school closure above 200, making the index a critical tool for protecting children during haze episodes.

Permenaker No. 5/2018

An Indonesian ministerial regulation on occupational heat exposure issued by the Ministry of Manpower. It sets permissible heat limits using a local heat stress index and requires employers to measure environmental conditions, adjust work–rest cycles and provide engineering controls. Enforcement, however, is concentrated on formal industrial settings and rarely extends to informal agricultural or platform-based workers.

Indonesian heat stress index (ISBB)

Indeks Suhu Basah dan Bola, the Indonesian wet-bulb globe temperature index used to assess workplace heat stress. It combines air temperature, humidity, wind speed and solar radiation into a single value that reflects the body’s cooling capacity. Permenaker No. 5/2018 defines work–rest regimes based on ISBB readings, linking regulatory action directly to measured thermal load.

PM2.5

Fine particulate matter with a diameter of 2.5 micrometres or less, small enough to penetrate deep into the lungs and enter the bloodstream. It is the main pollutant in Southeast Asia’s transboundary haze from forest and peatland fires. Chronic exposure is linked to respiratory and cardiovascular disease, and the World Health Organization’s annual guideline is 5 micrograms per cubic metre — a level regularly exceeded by a factor of five or more in major cities during dry-season fires.