Burning smell in September likely due to vapours called volatile organic compounds: Masagos

Burning smell in September likely due to vapours called volatile organic compounds: Masagos

The levels of the volatile organic compounds detected were well within international safety guidelines, the minister says.

strong smell ne singapore
A resident in Serangoon complained of a slight haze and a pungent chemical smell that "came quickly and was very strong" on Sep 25, 2017. (Photo: Channel NewsAsia reader)

SINGAPORE: Higher than usual levels of a type of vapours in the air were likely to have been behind a strange burning smell that affected some areas in Singapore in September, Minister for the Environment and Water Resources Masagos Zulkifli said on Monday (Nov 6).

Air monitoring sensors and air samples collected showed an increase in the levels of some volatile organic compounds (VOCs) – vapours which can come from both man-made and natural sources, and can cause smells by themselves or when they react with other volatile organic compounds, he said.

“The smell could also have been intensified by the light wind conditions during the period, and only dissipated later that night when winds blowing from the south and south-east picked up strength,” he said. He added that while there have been previous smell-related incidents in Singapore, this episode was more widespread.

Despite the increase, the levels of the VOCs detected were well within international safety guidelines, he said. 

He was responding to questions in Parliament from Members of Parliament (MPs) Gan Thiam Poh, Lee Bee Wah and Sun Xueling on the smell on Sep 25 this year, which left some residents in areas like Sengkang, Commonwealth and Serangoon with breathing difficulties and headaches.

The MPs asked for the cause of the smell and what Singaporeans should do in the event of a similar incident and whether there have been similar incidents previously.

Mr Masagos said that when the incident happened, the National Environment Agency informed its counterparts from the Malaysian Department of Environment in Johor of the incident and sought their assistance to locate the source of the smell. Following NEA’s request, the Johor authorities launched an investigation into the incident, he said.

The source of the smell was traced to a factory in Pasir Gudang. The Johor authorities issued a stop-work order against the operator of the facility and ordered the operator to carry out a list of remedial actions, Mr Masagos said.

The Malaysia media reported last month that the stop-work order was lifted after the operator had completed the necessary remedial actions.

“Tracing the source of fugitive smell is not a straight-forward process but requires time and effort,” Mr Masagos said. 

VOCs are typically released from burning fuel, such as gasoline, wood, coal, or natural gas. They are also emitted from oil and gas fields and diesel exhaust, and from solvents, paints and glues. Many VOCs are commonly used in paint thinners, lacquer thinners, moth repellents, air fresheners, hobby supplies, wood preservatives, aerosol sprays, degreasers, automotive products and dry cleaning fluids.

Ms Sun asked if there is any research done on the effects of persistent low-level exposure to such compounds, as the residents in her ward in Punggol live near Pasir Gudang. Mr Masagos said that no such research is available. 


Responding to MP Joan Pereira's question on how prepared Singapore is to deal with a chemical gas attack by terrorists, Mr Masagos said security agencies have plans in place.

The Singapore Civil Defence Force, for instance, regularly conducts exercises simulating chemical agent attacks where officers are tested for their proficiency in detection, monitoring and mitigation operations, he said. 

In incidents involving toxic gases, the response of the public is also important, Mr Masagos added. Those in the affected area may feel unwell or experience symptoms such as giddiness and shortness of breath.

They should quickly leave the affected area and, where possible, help evacuate others, before seeking medical attention, he said, attributing the advice to SCDF.

Those who are not able to leave should go to the nearest indoor place and take actions like "shutting the doors, windows and ventilation systems like fans and air conditioners, and seal the gaps with masking tape to minimise the infiltration of hazardous vapours".

Source: CNA/ja