SINGAPORE - Nine local kueh manufacturers that were penalised more than a week ago for using higher than permitted levels of preservatives have now all had their suspensions lifted.

The Singapore Food Agency (SFA) said on Wednesday (Aug 3) that the remaining four manufacturers who were still on the suspension list had provided test results which showed that their current production is free from benzoic or sorbic acid.

They were Chit Guan Foodstuff, Sin Hwa Coconuts Industrial, Tongli Food Manufacturing and Toh Chuan Kee Foodstuff.

The tests were conducted by accredited third-party laboratories, and adequate measures have since been put in place that comply with Singapore food regulations, said the SFA.

The nine had their operations suspended on July 26.

Sorbic and benzoic acid are chemicals used in food preservation and allowed in only the filling of kueh products, within permissible limits.

On July 28, Tiong Bahru Tian Bo Shui Kueh, which owns the popular Jian Bo brand of chwee kueh (steamed rice cakes), had its suspension lifted when it was able to produce test results showing its current products did not contain sorbic acid.

The SFA lifted its suspension on four more on Tuesday. They were Thomson Foodstuff Manufacturing, Delight Baker, AMK Nonya Kueh and Lim Food Industries.

The agency also said last Friday that it was reviewing internal procedures to ensure that food safety requirements are communicated accurately to manufacturers.

It said it had given incorrect information to Tiong Bahru Tian Bo Shui Kueh that a certain limit of sorbic acid was allowed in kueh products.

Notwithstanding the miscommunication, SFA's inspection in April found higher than permitted levels of sorbic acid in two of the manufacturer's kueh products.