• Multiple explosions at Leeden National Oxygen’s lab killed a 30-year-old chemist and injured at least seven other employees
• The firm and its chief executive officer pleaded guilty to one charge each of failing to take measures necessary to ensure the safety and health of its employees
• Investigations found that the firm was not allowed to store petroleum and flammable material, but they were stored there for easy access

SINGAPORE – A 2015 laboratory fire that caused multiple explosions at a gas manufacturing firm’s factory in the Jurong industrial area – killing a 30-year-old chemist and injuring at least seven other employees – broke out as an unqualified weld joint was used, a court heard on Tuesday (Dec 1).

Investigations also revealed that the firm, Leeden National Oxygen (Lnox), was not authorised to store petroleum and flammable material at its specialty gas centre quality control laboratory, but cylinders of combustible gases were stored there for easy access and retrieval during calibration or gas analysis.

A year before the fire broke out at the lab, an employee conducting a routine inspection had raised an issue over the facility’s gas leakage indication lights as they were blinking occasionally without any obvious triggers and were deemed unreliable in the event of an actual gas leak.

The employee, Mr Lee Mun Hong, then got a quote from a contractor for his proposal to revamp the entire gas detection system at Lnox in May 2015, but the work was not carried out. The employee was informed that the firm had no budget to perform such work and that the proposal would be pushed to the following year.

The accident took place at about 9.20am on Oct 12 in 2015, before the firm’s budget proposal for the following year.

Lab chemist Lim Siaw Chian, then 30, according to past reports, was carrying out gas analysis on a gas cylinder in the lab when there was a blast. Lim, who died from the explosion, was last seen to be touching a regulatory valve assembly (RVA).

The unqualified weld joint was found in the bullet stem of the RVA which she last touched.

These details emerged as Lnox and its chief executive officer Steven Tham Weng Cheong, 69, pleaded guilty to one charge each under the Workplace Safety and Health Act of failing to take measures that were necessary to ensure the safety and health of its employees at work.

Measures that they admitted that they had failed to put in place include ensuring that unsafe modified RVAs were not used when testing combustible gases, and that safety concerns raised in relation to the proposal to change the gas detection system at the workplace were addressed.

They also failed to provide adequate support and direction to the employees in respect of safety by failing to review safety procedures after the merger of Leeden Limited and National Oxygen Private Limited to form Lnox on Oct 1 in 2014, and failing to announce and appoint a staff member to assume the safety portfolio after Mr Gary Choo Pu Chang had resigned in August 2015.

An employee was tasked to assume Mr Choo’s portfolio temporarily, but investigations revealed that he did not have much involvement in safety. He was “merely an assistant to and reported to Tham”, and no announcements were made to clarify his role, said Ministry of Manpower prosecutor Erdiana Hazlina.

She added that there were no reviews of safety procedures after the merger and no inquiries were made into safety after Mr Choo’s resignation.

She said Tham was more focused on his other responsibilities relating to Lnox’s business and finance, and assumed that the major shareholder of Leeden and National Oxygen before they merged, Taiyo Nippon Sanso Corporation, had checked the safety processes before their amalgamation into Lnox.

There were multiple explosions at Lnox’s premises along Tanjong Kling Road on the day of the incident. Court documents stated that the initial explosion injured two of Lim’s colleagues who were performing similar works in the lab, apart from killing Lim, and secondary fires caused seven other employees to be injured.

Injuries included abrasions, eye globe rupture, lacerations and brain haemorrhage.

Ms Erdiana said the failure of the unqualified welded joint, which was not qualified and approved by a manufacturer, resulted in the leak of flammable gases including methane, oxygen and nitrogen from the RVA during the testing of the cylinder.

She added that the leaking gas mixture was most likely ignited by the frictional heat generated due to the escaping gas mixture, an internal sudden agitation of debris and particulate that flashed back into the cylinder, or a combination of both factors, causing “rapid overpressure” to build.

Subsequent fire and explosions probably occurred, she said, due to the ignition of carrier and supply gases released into the lab and the rupturing of cylinders that were stored on the premises due to the heat.

For committing the offence under the Act, a company can be fined up to S$500,000 while a person can be jailed for up to two years and fined up to S$200,000.

The prosecution is asking for Lnox to be fined S$380,000 and Tham to be fined S$50,000.

The parties will return to court on Jan 12 next year.