Mysterious Mist -- Boeing, Faa Deny Windshield Rain Repellent Is Toxic, But Critics Say Fumes Can Disable Unsuspecting Pilots

In the cockpit of every large jetliner flying, there is an innocuous-looking canister with a powder-blue label within arm's reach of the flight crew.

The canister holds Boeing Rain Repellent for Aircraft Windshields, or RainBoe, a liquid concoction used on planes since the mid-'60s to help pilots see better in foul weather.

Once thought to be virtually as benign as rainwater, RainBoe has become the subject of a stormy dispute rumbling through the aviation community.

At issue is whether RainBoe is safe - or a lethal poison that may have contributed to accidents in the past and continues to pose a threat to pilots and their passengers.

The controversy pits a small, but increasingly vocal, circle of pilots and safety experts against the bedrocks of the aviation-safety establishment, The Boeing Co. and the Federal Aviation Administration.

In this polarized debate, there is no middle ground.

Critics vehemently argue that RainBoe is an extremely hazardous toxin susceptible to leaking in high enough concentrations in the cockpit to disable the flight crew.

``This stuff is like a time bomb,'' said David Cronin, a retired United Airlines pilot with 34 years experience. ``The majority of pilots this very minute do not realize the hazard to which they are being exposed.''

Cronin said he was never given anything as a pilot to indicate the material was a possible hazard. ``But there is just so much hard evidence available to indicate that RainBoe is very, very toxic.''

Not true, say Boeing and the FAA, which has yet to act on a petition filed 20 months ago by the Air Line Pilots Association calling for stricter rules on the use of RainBoe and other toxic materials in the cockpit.

The company that invented RainBoe and the federal agency charged with ensuring that it is safe to use in commercial flying insist that the rules established 25 years ago for using RainBoe are adequate and need no upgrading.

``We believe it is very safe, and I haven't seen anything, anywhere that says anything different,'' said Boeing's top cockpit engineer Harty Stoll, who helped patent the RainBoe system in the early '60s.

Whichever side is right, the implication for air travelers is pervasive. Over the past two-and-a-half decades, RainBoe has become an industry standard. One or two 27-ounce canisters of RainBoe, connected to a pressurized system of tubes and fittings, can be found in the cockpit of every model of Boeing, McDonnell Douglas, Lockheed and Airbus jetliners - about 10,000 aircraft in all.

RainBoe is comprised 95 percent of Freon 113, a potent solvent used primarily as an industrial cleaner. Other types of freon are used in air conditioners, refrigerators and stereo-video parts cleansers. In RainBoe, Freon 113 is used as the carrying agent for chemicals that cause rain to glaze instantly off the cockpit windshield.

For decades, DuPont, the giant chemical company and principal manufacturer of Freon 113, marketed the liquid solvent as nontoxic.

But in recent years, federal occupational safety authorities have warned that Freon 113, which vaporizes rapidly, attacks the human central nervous system like a powerful narcotic, causing disorientation and forgetfulness, impairment to motor skills and, in cases of acute exposure, sudden heart attack.

Because Freon 113 vapors are invisible and emit only a slight, nondistinct odor, victims can be exposed to dangerously high concentrations without realizing it.

In May 1989, the National Institute of Occupational Safety and Health issued a nationwide alert to employers and labor unions, recounting 12 accidental deaths caused by acute exposure to Freon 113 in confined, poorly ventilated work areas.

Cronin and others speculate that, over the years, undetected cockpit leaks of Freon 113 may have been a factor in air tragedies chalked up to pilot error, especially in cases where otherwise reliable aviators performed irrationally.

``Every time I read in the newspaper about how some veteran pilot misjudged a distance or forgot some crucial task, which his life and the lives of his passengers depended on - like forgetting to set the flaps - or does some inexplicable thing like turn left into a mountain or taxi onto the wrong runway, I have to wonder about this stuff lurking in the cockpit,'' said Lance Schaeffer, a San Diego attorney.

As it turns out, Boeing is currently working on removing Freon 113 from RainBoe, but not because it believes the solvent is unsafe, said Stoll. Boeing researchers hope to come up with a nontoxic substitute for Freon 113 at the behest of the Environmental Protection Agency, which has ordered the phasing out of the solvent to protect the ozone, Stoll said.

The reformulated, freon-free version of RainBoe won't be ready for at least a year, Stoll said.

Meanwhile, Schaeffer and a client, USAir Captain Richard O'Harren, have waged an intense campaign to immediately remove RainBoe from the cockpit.

O'Harren spent the past six years battling Boeing in a products-liability lawsuit in which the pilot alleged that he suffered from hypertension after RainBoe leaked from the instrument panel of a McDonnell Douglas MD-80 jetliner on a Pacific Southwest Airline flight above Los Angeles. (PSA was subsequently acquired by USAir.) For more than a year after the incident, O'Harren suffered chronic nosebleeds and his blood pressure was so high that he couldn't pass the pilot recertification physical examination.

O'Harren testified that he was sprayed on his lap and in the face, but did not realize a leak was in progress until he banked into the sun and saw a fine mist in the air of the cockpit. He and the co-pilot, who suffered headaches but no long-term ill effects, immediately donned their oxygen masks, averting what might have evolved into a major air tragedy, said Schaeffer.

Last September, a six-month trial culminated with a San Diego jury ruling that O'Harren was, indeed, injured by RainBoe, awarding the pilot $2.45 million from USAir, McDonnell Douglas, Boeing and DuPont for physical injury and emotional distress. The biggest chunk of the award - $2 million - was assessed as punitive damages against USAir, which is appealing its part in the case.

Among its findings, the jury ruled that there was a defect in the RainBoe liquid and the pressurized cockpit dispensing system designed by Boeing, and that Boeing failed to adequately warn the pilot about the hazards of the product. Boeing paid O'Harren $317,000 in compensatory damages and legal fees and has agreed not to appeal the case.

O'Harren has returned to work, but took a $20,000 annual salary cut because he now refuses to fly anything but smaller British Aerospace BAC-146 jets, in which RainBoe is stored beneath the cockpit floor. USAir, exercising a clause of O'Harren's labor contract, has refused to grant the the pilot permission to be interviewed about the case, Schaeffer said.

Boeing continues to assert that RainBoe is essentially harmless.

``We believe sincerely that Captain O'Harren was not injured as a result of that (leaking) incident,'' said Bruce Campbell, the Perkins Coie attorney who led a team of lawyers defending Boeing in the case. ``We believe strongly that it is a very rare occasion where there is a leak and that, if there is a leak, you cannot get an appreciable concentration of the rain repellent in the pilot's breathing zone.''

Schaeffer bristles at what he describes as Boeing's ``arrogance'' and refusal to acknowledge the jury's verdict.

``They can deny this forever, but there's only one forum in this country for deciding conflicting claims and that is the legal system,'' he said. ``Boeing is well-versed in the legal system. They put up a vigorous defense. The jury heard the best Boeing had to offer and said, `We're not buying it.' ''

A pivotal issue in the trial - and in the ongoing debate - is whether it is possible for a toxic concentration of Freon 113 vapors to reach the pilot in the confined cockpit area, given the sophisticated ventilation systems used on modern jetliners.

The long-term ``permissible exposure limit'' assigned to Freon 113 by the Occupational Safety and Health Administration is 1,000 parts per million. That means a worker should be able to breath air that has 1,000 parts Freon 113 to 1 million parts air for eight continuous hours, five days a week, with no ill effects. (Notably, 1,000 ppm was assigned to Freon 113 in the late 1970s; it is the exposure limit routinely assigned to chemicals generally thought to be nonhazardous. By comparison, benzene, another common industrial solvent and a proven carcinogen, has an exposure limit of 1 ppm.)

The National Institute of Occupational Safety and Health has assigned 4,500 ppm as the level at which the solvent should be considered ``immediately dangerous to life and health,'' and a 1968 study by the National Aeronautics and Space Administration concludes that exposure to as low as 200 ppm for 60 minutes has ``strong effects on manual dexterity and mental vigilance.''

Said Larry Reed, the institute's policy development director: ``Like most organic chemicals, Freon 113 has a central-nervous-system effect. It tends to act not unlike when one drinks alcohol.''

In fine print on the back of all canisters of RainBoe is this warning: ``Overexposure can cause central-nervous-system depression, anesthesia and cardiac sensitization.''

Boeing began putting the warning on the label in 1985 to meet new OSHA rules on informing workers about potentially dangerous substances in the workplace. However, the company issued no special alert to pilots or mechanics, most of whom have not noticed the change from the old, warning-free label, Cronin said.

So, in the event of a cockpit leak of RainBoe, what concentration of Freon 113 might reach the pilot?

Never more than a negligible amount, or enough to kill him or her four times over - depending on which set of tests you believe.

During the O'Harren trial, Boeing introduced as evidence results of a field test, which asserted that, given a rapid leak of the rain-repellent system in a MD-80 cockpit, the captain would be exposed to a maximum of 400 ppm and only for a few seconds before the vapors quickly dissipated.

Later, in a similar test carried out on a 737-500, Boeing's smallest cockpit, a series of leak tests produced a peak of 200 ppm in the captain's breathing zone, again only for a few seconds.

The tests, conducted by Boeing flight-test engineers and attended by FAA inspectors, involved spraying a can of RainBoe into an open pan under the captain's seat with the cockpit ventilation system operating as if the plane were aloft, then measuring the air in the pilot's breathing zone.

Boeing is now using those test results in an attempt to convince the FAA to deny the pilots association petition for stricter rules on RainBoe use.

``We do not think that in normal day-to-day operation, the mechanic or the pilot will ever be exposed to more than 200 ppm,'' said Stoll, referring to Boeing jets.

Slightly higher concentrations are theoretically possible on McDonnell Douglas MD-80 and DC-9 jets, he said, because of differences in design of the instrument panel and dispensing system.

O'Harren's lawyers attacked Boeing's MD-80 field tests during the trial, even going so far as questioning whether the test canister truly contained RainBoe and whether the measuring device was calibrated properly.

Schaeffer stressed that a reading taken from vapors emitted from a small open pan would be significantly lower than from Freon 113 splattered over a wide area of the cabin, or spewing under pressure from a leak in the system directly into the pilots breathing zone. He produced extensive mathematical analyses of the MD-80 cockpit air-flow patterns that contradicted the Boeing test results.

Dr. Behzad Samimi, head of the occupation and environment division of the San Diego State University Graduate School of Public Health, calculated that a steady leak of 13 ounces, or about half a canister of RainBoe, would expose the flight crew to 7,000 ppm - nearly twice a potentially lethal dose of Freon 113. A continuous leak of 40 ounces (one-and-a-half canisters; the MD-80 has a two-canister system) would produce an exposure of 20,000 ppm, Samimi's analysis showed.

In one case cited in the alert by the National Institute of Occupational Safety and Health, a worker who climbed into a military tank after it had been flushed with Freon 113 lost consciousness and died of a heart attack after being exposed to 7,600 ppm of the solvent for about one minute. Workers who entered the tank to retrieve the victim reported nearly being overcome by the vapors.

Samini noted that his calculations were based on a leak occurring evenly over 130 minutes with the cockpit ventilation system operating normally, and that he could postulate even more dire scenarios: ``If the freon is squirted all over the warm instrument panel, you create a wide surface of evaporation'' as the liquid becomes a gas. ``The larger the surface of evaporation, the higher the rate of evaporation, which means a higher concentration.

``An exposure of 2,500 ppm, which would begin to affect the psycho/motor functions, could rather easily and quickly be reached within the cockpit due to a small, undetectable leak.''

Boeing doesn't buy it. Said Stoll: ``There are about five different people, including Boeing, who did mathematical tests and they all were wrong.'' Stoll said no mathematical thesis could accurately depict the way Freon 113 molecules behave in the ventilated cockpit air and that such tests tend to show high concentrations that cannot be recreated in actual field testing.

Boeing officials also point out that there have been only six to eight leaks of the rain-repellent system reported during flight and another six to eight reported on the ground in the 25 years RainBoe has been in use.

Among the causes for leaks: a crew member using the canister as a foot rest; a crew member trying to kick a loose canister back into position; a corroded canister, two years past its expiration date, springing a leak; a mechanic inadvertently leaving off an important fitting.

FAA spokesman Dave Duff emphasized that the O'Harren incident is the only case on record of a serious injury linked to a RainBoe leak.

Even so, the airline pilots association, prompted by the O'Harren lawsuit, filed a petition July 5, 1989, asking the FAA to order Boeing to add ``a distinctive odor'' to RainBoe as a warning device, to require airlines and manufacturers to more extensively shield canisters and dispensing lines, and to order more extensive and frequent testing of rain-repellent dispensing systems.

Boeing contends that the existing rules, which call for the system to be checked during major overhauls, are more than adequate.

``I don't think, no matter what we do, we can do better than six leaks in 25 years and 300 million flight hours,'' Stoll said.

Stoll said relocating the canister beneath the cockpit floor, as some have suggested, was a bad idea because the electrical gauges needed to keep track of the fluid would cut the system's reliability by half.

He said Boeing was opposed to shielding the canister - mounted in the open on the rear cockpit wall of most Boeing planes - because, ``Mechanics would just leave the shroud off.''

He said ``odorizing'' RainBoe was ill-advised because a pungent smell might distract the pilot, should the system spring a leak during a critical phase of the flight.

``He doesn't need to know there's a leak if he's landing your airplane. Even if there is a massive leak, it will not hurt him,'' Stoll said. ``If he gets distracted and starts working the leak, particularly in foul weather, you're going to create crashes that'll kill everybody.''

Boeing Senior Vice President Ben Cosgrove said the company, despite its formal opposition to the pilots' petition, is considering adding a more distinct odor to the version of RainBoe being reformulated to meet EPA ozone-protection rules.

But Schaeffer is worried that Boeing may downplay hazards of whatever substance emerges as the substitute for Freon 113. ``They still deny that this stuff is dangerous; that tells me that they are not trustworthy,'' he said. ``Why should I have any confidence that the reformulated version will be safe?''

The FAA, at this point, apparently agrees with Boeing that RainBoe is harmless as is. The public comment period on the pilots' petition ended more than a year ago. Since then, the request has remained ``under legal review'' by the agency. Duff said there was no word on when the agency might respond to the petition.

Yet, top FAA officials have been sending letters to senators and members of congress, alerted to the issue by Schaeffer, assuring lawmakers that the agency has tested RainBoe - a reference to witnessing the disputed Boeing field tests - and concluded that the rain repellent ``is safe and provides a valuable safety benefit to aviation.''

Two FAA officials who wrote such letters as recently as last March - M.C. Beard, director of aircraft certification, and Anthony Broderick, associate administrator for regulation and certification - declined to be interviewed for this article.

``We feel the content of those letters represents the agency's current stance on the issue,'' said FAA spokesman Bob Buckhorn.

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FACTS ABOUT RAINBOE

RainBoe is a liquid compound that causes rain to instantly glaze off aircraft windshields. It is stored in a single 27-ounce canister inside the cockpit of most jets; McDonnell Douglas MD-80s and DC-9s have a two-canister system.

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Is RainBoe...

Harmless?

Field tests conducted by The Boeing Co. assert that a rapid leak of RainBoe in the cockpit of a Boeing jet would expose the pilot to no more than a harmless 200 ppm, given normal operation of the cockpit ventilation system.

or Lethal?

Mathematical analyses by Dr. Behzad Samimi, San Diego State University School of Public Health, show a steady leak over 130 minutes of half a canister of RainBoe would expose flight crew to 7,000 ppm, nearly twice a potentially lethal dose.

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-- Contents: 95% Freon 113, a common industrial solvent also known as CFC or trichlorotrifluorethane.

-- Properties: Freon 113 transforms quickly into an invisible, heavier-than-air vapor that lacks a distinct odor and is easy to get accustomed to.

-- Toxicity: Overexposure produces symptoms of drunkenness, disorientation, forgetfulness, and, in acute cases, sudden heart attack.

-- Exposure limits: Exposure to 1,000 parts per million deemed safe by OSHA; NASA study shows psycho/motor impairment possible at 200 ppm; 4,500 ppm potentially fatal

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On Boeing jets, much of the dispensing system runs under the cockpit floor, safely away from the crew. However, the canister is mounted openly of the back wall or under the captain's seat. Vapors from leaks near the canister or from the instrumental panel could reach the crew.

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A disabling leak

A failed fitting on board a PSA MD-80 jet caused RainBoe to spray through a gap in the instrument panel into the breathing zone of Richard O'Harren, who noticed the mist when he banked into the sun. The pilot donned his oxygen mask, averting potential disaster.

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The MD-80 dispensing system

Covering gap would prevent a repeat of the O'Harren incident. (Boeing jets do not have gaps.) Still, most of the MD-80s pressurized dispensing system remains housed under the panel susceptible to leaks. Meanwhile, the FAA has declined to toughen rules for RainBoe use.

Source: The Boeing Co.; Lance C. Schaffer