SINGAPORE - A risk assessment in 2011 of operations in a laboratory linked to a 2015 fatal blast was described as "perfunctory, simplistic and inadequate", a district court heard on Monday (Jan 24).

The explosion, which ripped through Leeden National Oxygen's laboratory in Tanjong Kling Road in Jurong on Oct 12, 2015, killed chemist Lim Siaw Chian. The incident left seven others injured.

Gary Choo Pu Chang, now 64, who is the former executive director of the industrial gas supply firm, is now contesting one charge under the Workplace Safety and Health Act.

He is accused of performing a negligent act which endangered the safety of others at the laboratory in the Specialty Gas Centre.

On the first day of his trial on Monday, the court heard that the Singaporean allegedly failed to ensure that an adequate risk assessment was conducted in respect of the operations of the laboratory.

He is also said to have failed to ensure that there was a system for the tracking and maintenance of the regulatory valve assemblies (RVAs) used there.

In January last year Leeden National Oxygen was fined $340,000 and Mr Steven Tham Weng Cheong, who was the company's managing director, was fined $45,000, over workplace safety lapses.

The company and Mr Tham, then 69, were each convicted of an offence under the Act in December 2020.

On Monday, Ministry of Manpower prosecutor Samuel Chua told the court that on Nov 7, 2011, a risk assessment was conducted for an analysis of flammable gases in the laboratory. It was not mentioned who conducted it.

A manager at the laboratory reviewed and approved the assessment on March 7, 2014.It was not mentioned if the assessment had also been reviewed and approved earlier.

Mr Chua added: "Investigations revealed that the risk assessment... was perfunctory, simplistic and inadequate... The work activities in the laboratory for which risk assessment was necessary ought to have included the temporary placement of gas cylinders in the laboratory for the purpose of sample-testing their contents."

He also said that risk control measures to address the work activities and their hazards ought to have included items such as the proper tracking of RVAs as well as their proper identification and labelling.

Mr Chua told District Judge Kamala Ponnampalam: "Where experience in risk assessment was lacking, (Leeden National Oxygen) should have engaged a workplace safety and health officer, (a) workplace safety and health auditor or (an) approved third-party consultant who was trained and experienced in conducting risk assessments to assist (the company's)... team."

Leeden National Oxygen was established on Oct 1, 2014 following the merger of two firms - Leeden and National Oxygen.

Before the merger, Choo was National Oxygen's deputy managing director, and oversaw several departments, including the laboratory.

After the merger, he became the executive director of the new company.

Choo resigned on Aug 12, 2015, two months before the fatal blast on Oct 12 that year.

Mr Chua told Judge Kamala: "At the material time, (Ms Lim) who was employed as a chemist... was carrying out a gas analysis on a gas cylinder in the laboratory.

"The initial explosion killed the deceased instantly and injured three of her colleagues, who were also working in the laboratory. The incident further resulted in injuries to four other employees of (Leeden National Oxygen)."

Earlier, The Straits Times reported that Ms Lim had returned to work from maternity leave a week before the tragedy.

The former Malaysian had received her Singapore citizenship just a month before she died.

Her charred remains were found on six occasions over a two-month period after the incident and they were identified using her daughter's DNA. Her baby was six months old at the time.

In 2016, then State Coroner Marvin Bay found that Ms Lim's death was an industrial misadventure.

Mr Chua said on Monday that closed-circuit television (CCTV) footage showed that the initial explosion occurred towards the rear of the laboratory.

Ms Lim was last seen touching an RVA connected to a gas cylinder beside a gas chromatography machine before a bright light appeared.

The CCTV footage then went blank.

Choo is represented by lawyer Gregory Ong Lian Yi and the trial will resume on Tuesday.

If convicted of the offence under the Act, he can be jailed for up to two years and fined up to $30,000.