Investigation into Chemical Odour from Pasir Gudang

Ms Joan Pereira asked the Minister for the Environment and Water Resources with regard to the incident of a chemical stench from Pasir Gudang in September 2017 (a) what should Singaporeans do in the event of a similar incident; (b) how can they differentiate between gases which are toxic and non-toxic; (c) how can similar incidences be prevented; and (d) how well-prepared is Singapore to deal with a chemical gas attack by terrorists.

Er Dr Lee Bee Wah asked the Minister for the Environment and Water Resources (a) whether he can provide an update on the source and causes of the chemical odour and smoke detected in various parts of Singapore on 25 September 2017; (b) whether there is a long-term impact on public safety and health; (c) whether there have been previous similar incidents; and (d) what is the Ministry doing to safeguard our interests.

Ms Sun Xueling asked the Minister for the Environment and Water Resources with regard to the odour detected by many residents, particularly those living in the northeastern part of Singapore, on 25 September 2017 (a) whether the Ministry can provide more timely updates so that residents can take necessary precautions to protect themselves; (b) whether our current detection methods extend beyond smoke particles to dangerous chemicals; and (c) what advice can the Ministry give to Singaporeans to protect themselves in the event of dangerous chemicals in the air.

The National Environment Agency (NEA) maintains a network of real-time air quality monitoring stations across Singapore to detect air pollution. A number of these stations can measure low levels of Volatile Organic Compounds (VOCs) in the air. VOCs are vapours which can come from both man-made and natural sources, and they can cause smells by themselves or when they react with other VOCs.

NEA supplements the air monitoring stations by deploying officers to affected areas. These officers are equipped with portable instruments which can measure the levels of chemical compounds in the air. The Singapore Civil Defence Force (SCDF) is also equipped with portable sensors to detect and identify toxic gases, including chemical warfare agents, in the air.

In the late afternoon of 25 September 2017, members of the public reported smells in the Punggol and Sengkang areas. Similar reports were received from the northern and central parts of Singapore later in the evening, such as Ang Mo Kio, Toa Payoh and Bukit Timah.

Upon receipt of the public reports, officers from NEA and SCDF were immediately deployed to check that the air at the affected locations was safe. The officers also conducted investigations at nearby housing estates, factories and construction sites. Both the air monitoring sensors and the air samples collected showed an increase in the levels of some VOCs in the evening of 25 September, which likely caused the smell experienced. 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 southeast picked up strength. While there have been previous smell-related incidents, this episode was more widely spread across the island.

In their investigations, NEA and SCDF did not detect any build-up of harmful gases in the air or find any abnormal factory operations or incidents that could have caused the smells. Despite the increase, the levels of the VOCs detected were also well within international safety guidelines. Once this was established, the public was informed that the air was safe. At the same time, NEA informed its counterparts from the Malaysian Department of Environment (DOE) in Johor of the incident and sought their assistance to locate the possible source of the smell.

Following NEA's request for assistance, the DOE in Johor deployed its assets to investigate the incident. The source of the smell was finally traced to a factory in Pasir Gudang. A stop work order was issued against the operator of that facility by DOE and the operator was required to carry out a list of remedial actions. The Malaysia media reported on 6 October 2017 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 and requires time and effort. After NEA reached out to DOE, the Malaysians reacted quickly to carry out site investigation, trace the source of the smell and take the necessary actions on the facility to rectify the problem. We appreciate their cooperation.

Industrial premises in Singapore must comply with strict regulations and guidelines on the storage and transportation of hazardous materials. For example, the Environmental Protection and Management Act (EPMA) imposes requirements on the storage, use and transport of hazardous substances. These include putting emergency plans in place and preparing adequate emergency response equipment. These control measures are similar to those adopted in other jurisdictions, with each country adapting them to local requirements.

Let me now address incidents involving terrorist attacks using chemical gases. Our agencies are prepared for such a scenario. The SCDF regularly conducts exercises simulating chemical agent attacks where responders are tested for their proficiency in detection, monitoring and mitigation operations. In incidents involving toxic gases, the response of the public is equally important. Those in the affected area may feel unwell or experience symptoms, such as giddiness and shortness of breath. SCDF’s advice is that they should quickly leave the affected area and, where possible, help evacuate others, before seeking medical attention. For those who are unable to leave the affected area, they should go to the nearest indoor area and adopt In-Place Protection Procedures (IPP) by shutting the doors, windows and ventilation systems, like fans and air conditioners, and sealing the gaps with masking tape to minimise the infiltration of hazardous vapours.

SCDF will also send out alerts to notify the public to take the necessary precautionary measures. This alert will be sent out through all the public warning platforms, including social media, the SGSecure app and all the free-to-air frequency modulation (FM) radio and television channels. The "Important Message" signal of the Public Warning System may also be activated.

To learn more about how to respond in the event of an incident involving toxic gases, the public is encouraged to participate in the SCDF’s Community Emergency Preparedness Programme (CEPP). CEPP trains about 40,000 participants each year, and IPP is one of the advanced programme modules. Members of the public can learn to prepare an IPP kit, as well as how they can apply IPP against a chemical gas attack. More information on IPP can be found in the Civil Defence Emergency Handbook, which can be downloaded from the SCDF website.

These are among the measures that NEA and SCDF have put in place to safeguard the health and safety of Singaporeans.

Mr Speaker, I have one supplementary question. Just now, the Minister mentioned that the test showed that the air was safe. I would like to ask whether the test was conducted as a result of feedback from residents or do we have a station that constantly monitors the volatile organic chemicals and particulate matter (PM) 2.5. In the northern part of Singapore like Yishun, we will be affected first if there is anything that comes from Malaysia.

I thank the Member for the supplementary question. Yes, air is constantly monitored and tests are conducted for hazardous levels of VOCs to ensure that we are breathing air that will not be deleterious to our long-term health. Certainly, we have enough of these and if we find that we need to build more of such monitoring stations on the advice of consultants or otherwise, we will do so.

I thank the Minister for his reply. I understand that it takes time to trace the source of the noxious smell in the air, but I think our residents will appreciate a timely update on what chemicals are in the air, to aid their own assessment of what they can do to protect themselves. That is my first point. And my question is whether there is any research done on long-term exposure to low levels of VOCs in the air. I asked this because residents in Punggol and Sengkang obviously live closer to Pasir Gudang, and there are a lot of feedback or persistent concerns about such chemicals in the air. Even though at any one point in time, such VOC levels may be low and not cause immediate alarm, long-term exposure to VOCs may cause and endanger health.

The safety threshold of most VOCs is available only for occupational exposure, that means, when you are working in a situation where there are a lot of these VOCs, and you will be exposed to at least around eight hours of hazardous levels. Those studies are available. Studies which are connected with low constant exposure to these VOCs are not yet available or have not been done, so we cannot rely on such reports to produce any guidelines for our authorities to implement.