SINGAPORE - As the Republic looks set to enter a seventh day of unhealthy air quality on Friday (Sept 20) for some parts of the country, several companies with employees working outdoors are taking measures to protect staff.

Construction firms, security companies and beachfront businesses that The Straits Times spoke to on Thursday said they have taken steps including giving out N95 masks to employees and conducting haze awareness training for staff.

Air quality here hit unhealthy levels for the first time in three years last Saturday and has fluctuated over the past few days.

Going by forecasts the National Environment Agency (NEA) issued on Thursday evening, air quality in the next 24 hours could be similar to that for most of Thursday.

The 1-hr PM2.5 concentration readings are expected to remain in the normal band, while the 24-hour Pollutant Standards Index (PSI) is forecast to be between the high end of the moderate range and low end of the unhealthy range.

But if haze from the surrounding region is blown in, the 1-hr PM2.5 reading could enter the elevated band.

Even so, this could be an improvement from when air quality worsened on Wednesday and early Thursday.

The PM2.5 reading was 93 to 139 micrograms per cubic m in the elevated range at 12am on Thursday, while the 24-hour PSI hit 154 in the middle of the unhealthy band in the south from 2am to 4am.

But air quality improved later, with NEA saying on Thursday that this was due to stronger winds blowing from the south-east that helped to disperse the haze away from Singapore.

By 11pm, the 1-hour PM2.5 reading was 13-31 micrograms per cubic m, within the normal band, and the 24-hour PSI reading was 79-87, in the moderate range.

Some companies with staff working outdoors are not taking chances and have taken steps to make sure their workers are equipped to deal with the haze.

At beachside restaurant and bar Tanjong Beach Club, staff who work outdoors are given breaks every two hours for them to hydrate and rest indoors. Elderly staff and those who are pregnant have also had their staffing schedules changed to keep them indoors.

Mr Andrew Ing, chief operating officer of The Lo & Behold Group, which operates the beach club, said: "Each of our concepts, whether indoor or outdoor, has been equipped with N95 masks for staff and customers. With close hourly monitoring of the PSI, we are well prepared to close or reduce operating hours of certain outdoor sections as well if the air quality reaches unhealthy levels."

At Sentosa, N95 face masks and eye drops have been made available to all staff. A Sentosa Development Corporation spokesman said health advisories based on the 24-hour PSI will be displayed at key outdoor locations should the haze reach unhealthy levels and visitors who feel unwell can approach Sentosa rangers or service ambassadors for assistance.

Over at Lum Chang Building Contractors, its managing director Tan Wey Pin said the company has issued N95 masks to all its staff as well.

"Our safety personnel at the sites monitor the PSI Index on a daily basis and conduct risk assessments," he said. The construction company has also done haze awareness training at all their project sites to ensure that workers are aware of the risk, as well as safe working procedures.

He added that workers are also encouraged to take more frequent breaks, and that those feeling unwell are advised to stop work and see a doctor.

The Singapore Contractors Association has sent out a haze advisory to its 3,200 members advising all construction firms to continually monitor the haze condition and abide by Ministry of Manpower guidelines, said association president Ng Yek Meng.

These include reducing outdoor work when necessary and rotating worker's outdoor shifts to prevent prolonged exposure to the haze.

Local security firms and cleaning companies said they have also distributed masks to their workers, and issued advisories to employees to take precautions against the haze situation.

Mr Ong Kok Leong, group general manager of security firm Apro Asian Protection, said that N95 masks were given to all 1,300 employees at about 250 sites across the island, including schools, commercial and industrial buildings since last Wednesday. He added that about 50 per cent of the firm's workers would have outdoor exposure in their daily work.

"Our operations management team visits the sites on a weekly basis and deliver more (masks) once they are low in stock at the sites," said Mr Ong, adding that there are plans to cancel external patrol duties and for officers to remain indoors unless attending to vehicle or human traffic, if the 24-hour PSI reading enters the hazardous level.

As of press time, the upcoming Singapore Airlines Singapore Grand Prix will continue despite the haze. A spokesman for race promoter Singapore GP told ST this week that the race remains on track to proceed and the race organiser continues to monitor the ongoing haze situation.

And if it is required, the Ministry of Health said on Thursday that the Government has a national stockpile of 16 million N95 masks that can be released to the market.