On its own, Merck issued only a luke warm Vioxx warning.

In some cases, experts say, such warnings on Vioxx's official labeling aren't sufficient. Since 2002, Merck's Vioxx warning mentioned increased cardiac risks based on results of its own post-approval study, but disputed its own findings and drug remained on market despite Vioxx warning. Merck undertook latest study because less-rigorous experiments indicated Vioxx could prevent recurrence of potentially cancerous colon polyps, said company spokesman Tony Plohoros.

Dr. Alastair Wood, professor of pharmacology and associate dean at Vanderbilt University School of Medicine, said it should not have taken so long for heart risks to come to light. Had they come to light sooner, proper Vioxx warnings would have been issued.

People were hurt by inadequate Vioxx warnings "A helluva lot of people got drug between 2000 and 2004, and a very quick, very cheap study would have determined that risk" had FDA taken a tougher stance after first sign of trouble, Wood said. If better studies were performed, Vioxx warnings would have been more stringent -- or drug would not have been on market at all.

"In addition to health hazards of metal welding fumes and toxic gases, welding operations involve hazard of burns from flame, arc, molten metal, heated surfaces and also that of metal splatter. ...When personal respiratory protection is required, this may be provided by a supplied-air welding hood or, when components and concentration of fume are known, by a filter-type respirator with filter for protection against welding fumes. It is preferable, of course, that adequate ventilation be provided so as to make use of respirators unnecessary.

"When sampling for welding fumes, inspector will use a filter cassette placed on collar or shoulder so that it is beneath helmet when helmet is placed down. The sampling pump is fastened to belt. Samples [for welding fumes] may be full shift or short-term. Short-term samples may be taken to evaluate toxic [welding fume] components which have short-term limits. In addition, inspector may sample for toxic gases such as ozone, nitrogen oxides or phosgene. It is important that welder carry out welding operation in a normal way, so that an accurate evaluation of exposure can be made. The inspector will attach and remove filter cassette and pump as required.

"Normally, good local or general ventilation is required to control exposures to metal welding fumes and gases of welding operations. The most effective control is local exhaust ventilation in which an exhaust hood is placed near welding arc or flame, and ‘welding fume contaminants’ are drawn away from welder's breathing zone. The system may consist of moveable exhaust hoods, flexible and stationary ducts, a powered fan, and a welding fume or dust collector. Exhausted air containing welding fumes should be discharged to outdoors, if possible. It is important that, during welding operation, exhaust hoods are placed or set so that welding fumes are not drawn across worker's face or into breathing zone. Good general ventilation should be provided. Welding in confined spaces, such as tanks, cabs of mobile equipment and large shovels, may be especially hazardous and require additional ventilation to reduce welding fumes.”

http://www.msha.gov/S&HINFO/HHICM10.HTMCitation as of 11-15-2004.