A total of 67 factories were identified as operating without licence in Pasir Gudang, said Johor exco for local government, urban wellbeing and environment Tan Chen Choon.
Tan said this was discovered during the integrated operations by various agencies following the recurrence of vomiting and breathing difficulties in the Pasir Gudang area since June 20.
Of the 67 factories, eight will be subjected to court action, 46 were given warning notice, three were sealed, and two ordered to close.
Necessary action is being taken against the remaining eight, he told reporters after an enforcement operation on four factories in Pasir Gudang today.
The operation involved the police, Environment Department, Immigration Department and the Pasir Gudang Municipal Council.
One of the factories operating without a licence is involved in recycling plastic waste, including those imported from Ireland and the United Kingdom, he added.
During the operation, 12 illegal immigrants, comprising Bangladeshi, Indonesian and Chinese nationals, were detained.