At 6am, the 24-hour PSI in central Singapore was 221, while readings in the rest of the country were at the unhealthy level, ranging from 145 to 193.
SINGAPORE: Twenty-four-hour Pollutant Standards Index (PSI) readings rose overnight across Singapore, with the reading in the central region reaching the "very unhealthy" level at midnight on Friday (Oct 16).
At 6am, the 24-hour PSI in central Singapore was 221, while readings in the rest of the country were at the unhealthy level, ranging from 145 to 193.
The 1-hour PM2.5 reading in the eastern region jumped into the high band at 5am, and stood at 160 at 6am.
Hourly PM2.5 readings in other regions were in the elevated band, ranging from 99 to 150.
Prime Minister Lawrence Wong said on Thursday that Singapore is looking into which companies may be responsible for the forest and peatland fires in Indonesia that have caused the worsening haze.
"Where warranted, we will take action under Singapore’s Transboundary Haze Pollution Act, and explore joint action with other countries," he said in a social media post.
On Thursday, the 24-hour PSI peaked at 212 in the west – a new high for Singapore this year.
On Wednesday, 1-hour PM2.5 readings spiked around the country, with the reading in the west rising to a level not seen in Singapore since 2015. It stood in the very high band for most of the hours from 2pm to 8pm, peaking at 288
During a severe haze episode in October 2015, Singapore recorded an hourly PM2.5 reading of 471 in the western region at 11pm on Oct 19.
It is the highest reading in the publicly available log of hourly PM2.5 readings published by the National Environment Agency (NEA), which dates back to April 2014.
The government on Wednesday brought forward the phased distribution of masks to vulnerable Singaporeans after the PM2.5 reading in the west reached the very high band.
The Haze Task Force had earlier said last Friday that N95 masks would be distributed to more vulnerable individuals when the 24-hour PSI exceeded 200 and entered the very unhealthy range.
Minister for Sustainability and the Environment Grace Fu said the mask distribution exercise was launched early because the government had forecast that 1-hour PM2.5 readings were "likely to continue spiking". This would bring up 24-hour PSI readings as well.
Haze shelters at community clubs and selected Residents' Committee and Residents' Network centres have also been set up.
N95 mask distribution will commence in phases at community clubs and haze mask vending machines at selected public transport hubs, social service offices and People's Association venues, NEA said.
The masks will be made available progressively at designated collection points and may not be immediately available at all locations, the agency added.
"The vending machines are being progressively deployed across the island from this evening and stocks will be replenished progressively and regularly," it said.
Members of the public can visit the HazeMaskGoWhere website for more information on collection locations and live updates on mask availability at the vending machines.
"Members of the public are encouraged to check the website for availability before heading to a collection point," NEA said.
NEA also noted that N95 masks may be unavailable at some retail outlets due to a spike in demand, but said that "there are sufficient stocks of N95 masks in retailers' warehouses and government stockpiles".
"The Haze Task Force is working closely with retailers to replenish stocks and ensure the availability of N95 masks to the public," the agency added.