Meanwhile, other operators whose plants are located in Rayong and Chon Buri but outside Map Ta Phut are asking for more details, particularly the areas in which Industry Minister Kosit Panpiemras has asked for a halt to new projects.

"It's time for operators to strictly verify their environmental-control systems for the sake of the country," Santi said.

He said he had agreed with Kosit to suspend the construction of new plants until pollution problems were solved but the minister should not include projects that did not generate pollution.

"I don't believe the industry minister meant to delay every industrial project in Rayong. I'm quite sure that he meant only petrochemical projects," said Viboon Kromadit, senior vice president of Amata Corp, which operates the Amata Industrial Estate in Rayong province.

However, he said pollution problems happened because operators lacked awareness and social responsibility. "If operators insist that they do everything according to fixed standards, they should be able to prove this and show the results," he said.

Nevertheless, the public sector has yet to identify which standards to enforce with respect to toxic chemicals such as volatile organic compounds, he said.

Hence, the authorities involved must quickly set these standards, which should be the highest adhered to by companies world-wide, he added.

Viboon said the government should solve pollution problems as soon as possible to bring back investor confidence.

He said his company was facing a tough situation at the moment because of critical incidents like the Bangkok bomb blasts and the interim government's economic policies.

"Every investor prefers a bright sky to a cloudy one," he said. "If they have to ask: 'What will happen tomorrow?' every day, will they be interested in investing here? I doubt if they care how good your company's credit is, but they do care how good the country's credit is."

Overseas investors like unclear situations just as little as Thai companies do, he added.

When The Nation phoned for an interview, executives of Thai Oil refused to talk for the time being. The company's public-relations executive said they would wait for more information from the industry minister at a seminar on Thursday chaired by Prime Minister Surayud Chulanont.

"Our plants are located in Chon Buri province, but we want to make sure what area of the Eastern Seaboard the industry minister means," the executive said.

Meanwhile, IRPC's chief executive Piti Yimprasert said he had engaged Shell Global Solutions to improve the company's plants' burning efficiency and environmental control and was considering spending Bt1.2 billion to Bt1.5 billion on four new 150-metre smokestacks to reduce its pollution emissions.

He added that IRPC had continued to expand investment in a US$200-million (Bt7.1 billion) electricity plant at its site in Rayong province by changing the raw material from coal to natural gas, which would not have any negative effect on the environment.

"We will sign a contract to buy natural gas from PTT this week," he said.

He added that he did not believe the Industry Ministry's policy of concern about pollution at Map Ta Phut Industrial Estate and other industrial estates in Rayong would affect IRPC's business-expansion plan.

However, he added that the company would have to increase its investment budget for installing environmental-safety systems in existing and new plants.

Chalida Ekvitthayavechnukul

The Nation