Bolstered by government policies that encourage the use of old industrial buildings, businesses for mini-storage facilities have grown tremendously over the years, catering to customers like Yung.

But as demand for such facilities grows, so does the need to regulate them.

“The staff say you can’t store dangerous goods inside but they don’t check if you actually do,” Yung, 28, said.

Fire safety standards for mini-storage facilities are in the spotlight after a blaze engulfed SC Storage facilities at the Amoycan Industrial Centre, a Ngau Tau Kok industrial building, on Tuesday. The inferno, which was still raging on Thursday night, claimed the lives of two firefighters – Thomas Cheung and Hui Chi-kit – while two more were in hospital with serious injuries.

A major obstacle for firemen was the layout of 200 mini-cubicles inside the facility, each separated by metal sheets storing unknown goods.

Kwun Tong district councillor Yip Hing-kwok said he and other people in the neighbourhood had seen hawkers pushing their carts with gas stoves into the Ngau Tau Kok buidling.

While Yip said he could not be sure if the hawkers had actually stored the gas stoves inside the facility, it would be dangerous if they had done so.

Last year Secretary for Development Paul Chan Mo-po said the Lands Department did not have statistics on the number of industrial buildings being used and rented out for mini-storage facilities.

But the number is understood to be significant. SC Storage, for example, has 60 facilities across Hong Kong and Macau since it began operations in 2001.

Concerns about safety in the facilities centre is heightened because many of them are located in old industrial buildings that have laxer safety standards.

In Hong Kong, industrial buildings completed before 1973 are not required to be fitted with automatic sprinkler systems. In the Ngau Tau Kok case, the eight-storey building did not have sprinklers installed because it was completed in 1961.

Another problem is that customers are not required to give store owners a list of the goods they stash in their cubicles, making it difficult to keep track of whether dangerous items are being kept inside.

At present, mini-storage areas can only be regulated under the land leases of buildings. They are considered a type of godown or warehouse. Industrial buildings without such stated use can be found to be in breach of the land lease. But as part of the government’s strategy to revitalise such structures, many have applied for changes to how they are used.

Since 2010, 68 applications to convert buildings from industrial purposes to business purposes have been approved. Eight proposals to redevelop industrial buildings have also received the green light since then.

They provided about 1.06 million square metres of floor area for commercial and other non-industrial use.

Luiga La Tona, executive director of Self Storage Association Asia, said the association was willing to work with the government if there was a need to set up a regulatory body for the industry.

“If the government and regulatory bodies see there is a need [to regulate self-storage spaces], then the industry is open to working with them,” he said.

His comments came as the government announced a citywide inspection of all mini-storage facilities earlier this week. A cross-departmental team will also study how fire safety standards can be strengthened. The government did not rule out the possibility of amending relevant laws to ensure safety standards would be improved.

RedBox Storage chief executive Matthew Chee said it was fair for the government to review and strengthen the laws, but he warned of an increase in business costs.

“The financial impact will obviously be tremendous,” he said. “A lot of investment went into the building, into the business.”

His staff walk through the premises every day as a daily routine to look for irregularities. But he admitted that it was “really difficult” to track if his clients had stored dangerous goods in their cubicles.

He said staff had confronted customers in the past when prohibited items, such as helium tanks or gas tanks, had been found.

Chee dismissed a report that accused his Sha Tin facility of not having sprinklers installed.

“The building has sprinklers … from day one,” he said.

There were a total of 1,540 water sprinkler heads in the Sha Tin location, which was inspected annually and maintained monthly, he added.

Institute of Architects board member Ivan Ho Man-yiu suggested making it mandatory for storage facilities to have a standard passageway width.

The government should also regulate the use of materials in storage units as suitable ones would be able to “compartmentalise” and contain a fire and prevent it from spreading out of control.

Fire safety expert Professor Cheung Kwok-pun of the department of architecture at the University of Hong Kong said fire services, buildings and lands department officers should step up monitoring by requiring operators of mini-storage areas to comply with specialised fire safety requirements.

“These mini-storage areas are very different from regular factory spaces. They have been divided into densely packed units by metal sheets in a tight space,” he said.

“[Firefighters] had no idea what was burning inside. It could have been chemicals and oil from things such as compact discs and perfumes, burning items that would have caused sudden increases in temperature.”

He called for both the fire services and buildings departments to require operators to install automatic water sprinklers and appropriate openings to release smoke and submit risk assessments on how they would facilitate a rescue or firefighting operation.

On Wednesday, Secretary for Security Lai Tung-kwok admitted that although fire safety standards had generally improved over the years, the law still did not require old industrial buildings to “fit modern-day safety requirements.” He said the government would not rule out amending legislation.