CHARLESTON, W.Va. -- Under pressure from Bayer CropScience, the U.S. Chemical Safety Board has canceled a public meeting where it planned to brief Kanawha Valley residents on its investigation of the August explosion that killed two Institute plant workers.

Board members had scheduled the meeting for March 19, and intended to discuss concerns about a methyl isocyanate tank located near the site of the deadly blast.

Two weeks ago, Bayer lawyers warned board members and agency staff that the company felt such information should not be discussed in a public forum.

Bayer lawyers cited an obscure maritime law that was intended to keep confidential documents prepared by Bayer for the specific purpose of deterring terrorist attacks on the Institute plant's barge loading facility.

John Bresland, the chemical board's chairman, said this week that his agency decided to call off the public meeting while it looks into Bayer's confidentiality claims.

"We decided it would be better to postpone the meeting and get this issue clarified," Bresland said in a Monday phone interview.

But chemical plant safety advocates were shocked by the board's decision. They said it raises concerns that the industry has discovered a new legal loophole that company attorneys may try to exploit to derail detailed investigations of plant accidents.

"We would hope that this does not become a precedent," said Rick Hind, who follows chemical safety issues for Greenpeace.

Maya Nye, a leader of the local group People Concerned about MIC, said this week, "I don't understand why this is top-secret information. But this seems to be consistent with Bayer's lack of communication with the community."

Robert C. Gombar, a Washington, D.C., attorney for Bayer, did not return a phone call Tuesday.

Tom Dover, Bayer's Institute plant spokesman, declined to answer detailed questions about the company's dealings with the Chemical Safety Board.

Word of the board's action comes as Saturday's deadline nears for another federal agency, the U.S. Occupational Safety and Health Administration, to issue any citations for violations it found related to the Aug. 28, 2008, explosion and fire. Under federal law, OSHA has six months from the date it starts an investigation to issue citations.

Plant worker Barry Withrow was killed in the explosion and a second employee, Bill Oxley, died about six weeks later at a burn center in Pittsburgh. Thousands of residents between South Charleston and the Putnam County line were advised to take shelter in their homes.

The explosion occurred in a unit where Bayer makes methomyl, which it then uses to produce Larvin, the company's brand name of the insecticide thiodicarb.

But the Institute plant is best known for its production and use of methyl isocyanate, or MIC, the chemical that killed thousands of people in a leak from a Union Carbide plant in Bhopal, India, in December 1984.

Bayer uses MIC to make methomyl, and the methomyl unit includes a tank that can hold up to 40,000 pounds of MIC, according to company disclosures filed with the U.S. Environmental Protection Agency. That storage tank is located 50 to 75 feet from the location of the August explosion, according to state and federal inspectors.

Safety board investigators were looking into that tank, and asking Bayer questions about whether it was in an unsafe location or had appropriate safety devices.

Board members had scheduled the meeting for March 19, and intended to discuss concerns about a methyl isocyanate tank located near the site of the deadly blast.

Two weeks ago, Bayer lawyers warned board members and agency staff that the company felt such information should not be discussed in a public forum.

Bayer lawyers cited an obscure maritime law that was intended to keep confidential documents prepared by Bayer for the specific purpose of deterring terrorist attacks on the Institute plant's barge loading facility.

John Bresland, the chemical board's chairman, said this week that his agency decided to call off the public meeting while it looks into Bayer's confidentiality claims.

"We decided it would be better to postpone the meeting and get this issue clarified," Bresland said in a Monday phone interview.

But chemical plant safety advocates were shocked by the board's decision. They said it raises concerns that the industry has discovered a new legal loophole that company attorneys may try to exploit to derail detailed investigations of plant accidents.

"We would hope that this does not become a precedent," said Rick Hind, who follows chemical safety issues for Greenpeace.

Maya Nye, a leader of the local group People Concerned about MIC, said this week, "I don't understand why this is top-secret information. But this seems to be consistent with Bayer's lack of communication with the community."

Robert C. Gombar, a Washington, D.C., attorney for Bayer, did not return a phone call Tuesday.

Tom Dover, Bayer's Institute plant spokesman, declined to answer detailed questions about the company's dealings with the Chemical Safety Board.

Word of the board's action comes as Saturday's deadline nears for another federal agency, the U.S. Occupational Safety and Health Administration, to issue any citations for violations it found related to the Aug. 28, 2008, explosion and fire. Under federal law, OSHA has six months from the date it starts an investigation to issue citations.

Plant worker Barry Withrow was killed in the explosion and a second employee, Bill Oxley, died about six weeks later at a burn center in Pittsburgh. Thousands of residents between South Charleston and the Putnam County line were advised to take shelter in their homes.

The explosion occurred in a unit where Bayer makes methomyl, which it then uses to produce Larvin, the company's brand name of the insecticide thiodicarb.

But the Institute plant is best known for its production and use of methyl isocyanate, or MIC, the chemical that killed thousands of people in a leak from a Union Carbide plant in Bhopal, India, in December 1984.

Bayer uses MIC to make methomyl, and the methomyl unit includes a tank that can hold up to 40,000 pounds of MIC, according to company disclosures filed with the U.S. Environmental Protection Agency. That storage tank is located 50 to 75 feet from the location of the August explosion, according to state and federal inspectors.

Safety board investigators were looking into that tank, and asking Bayer questions about whether it was in an unsafe location or had appropriate safety devices.

Among the board's questions, Bresland said this week, was, "Should it be in that location or more remote from where there would be a potential explosion?

"That is certainly something we would be looking into," Bresland said.

But Bayer lawyers told safety board officials at a Feb. 12 meeting that any information about MIC handling and storage was protected from public disclosure under the Coast Guard's rules to implement the 2002 Maritime Transportation Security Act. But that law and the Coast Guard's rules appear to apply only to reports and data specifically put together by Bayer in planning its facility security plans.

Dover, the Bayer spokesman, confirmed that the company believes the Institute plant is covered by the Coast Guard rules. Dover added that there is information in the plant's security plant that the Coast Guard believes should not be released.

But Dover declined to offer any examples of what information he was talking about, or to explain what information the chemical board might have made public from the plant's security plan.

Dover referred further questions to the Coast Guard, but officials there did not respond to requests for comment.

Paul Orum, a longtime chemical industry watchdog in Washington, said he would be very surprised if Coast Guard regulations protected the kind of information the chemical board planned to share with the public.

"I don't know of any basis for what they're claiming," Orum said.

Bresland said Bayer officials also expressed concern about possible negative media coverage from a public meeting, and worried the meeting would veer into a broader debate over the Institute plant's storage of large amounts of MIC.

"They realized that a public meeting would have some negative consequences for Bayer," Bresland said.

Internally, chemical safety board officials were already discussing whether their probe should include an examination of the longstanding issues over MIC stockpiles at the Institute facility.

Bayer reports to EPA that it stores between 100,000 and 999,999 pounds of MIC at the plant. And for years, local and international activists have urged various plant owners to reduce that stockpile, as other chemical makers and some other Bayer facilities have done.

The major MIC storage tanks are underground and on the other side of the plant from where the August explosion occurred. Those tanks store an average of about 200,000 pounds of the chemical, according to EPA documents.

But Fred Millar, another longtime chemical company watchdog, wondered whether Bayer should have the smaller MIC tank located above ground near the methomyl unit that blew up in August.

"It feels like you've got a situation where the plant was caught with its pants down, and there's a questionable practice of storing this methyl isocyanate far too close to a dangerous reactive chemical unit," Millar said Tuesday. "This is no time for the Chemical Safety Board to be delaying talking about this to the public."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.