The regulation requires that factories discharging more than 500 cubic metres of waste water daily must install online biological oxygen demand (BOD) meters by the end of this year or risk losing their licences.

Introduced in 2004, the regulation intends to strictly prevent industrial waste from damaging the environment and communities nearby by keeping a closer track of discharges by factories and their contamination levels.

The Federation of Thai Industries (FTI) led its members to file the petition on the issue to Industry Minister Pracha Promnok yesterday.

"Each factory will need to pay about two million baht for the treatment system and small operators can not afford it, especially in a tough economy right now. We also think the ministry's pollution controls on factories [before the regulation] are good enough already and it is unnecessarily to have another regulation," Payungsak Chartsutipol, an FTI vice-chairman.

A preliminary survey by the FTI found that almost 400 factories nationwide will need to comply with the new rule.

"Only 62 factories have installed the systems and the rest are in a rush as the deadline for the installation is only a month away," Mr Payungsak said.

The FTI members also proposed that the burden to install such systems should fall on the government, adding that almost 70% of waste water came from communities while factories contributed the rest.

Mr Payungsak said the ministry had taken their proposals for consideration and might consider delaying the deadline, possibly by another 18 months.

A committee will also be established to work out the possibility of producing similar machines locally to lower the cost. The ministry would also consider support measures to help small and medium-sized operators, he said.