AFS, industry examine air emissions.

With the Clean Air Act Amendments of 1990 taking effect in 1997 for iron and steel foundries, toxic air emissions dominated this year's environmental control sessions.

The amendments will set new regulations for air emissions from foundries for 189 hazardous air pollutants (HAP).

A presentation by M. McKinley, I. Jefcoat, W. Herz and C. Frederic, University of Alabama--Tuscaloosa, summed up AFS' first-year research on air emissions from foundry waste streams.

AFS surveyed the metalcasting industry to identify and categorize the origin of foundry waste streams of environmental concern. The research included a review of all available information from technical literature, foundry chemical suppliers, AFS workshops, the EPA, technical meetings and visits to foundries.

Sand system waste led the list, followed by emissions from molding, pouring, melting and shakeout in iron and green sand steel foundries. However, no emission data exist for shakeout, the authors said.

Researchers also found that binder systems used in core and mold production are the most likely source for the emission of the chemicals on EPA's list of hazardous air pollutants.

"An idea of the complexity of the airborne emission problem from resin binders can be judged from the fact that there are some 19 different families of resin binder systems in commercial use in foundries today," the authors noted, adding that green sand was not counted as a resin binder even though it may be another toxic emission source.

Overall, more research is needed to determine the important parameters that control HAP emissions, they concluded.

In a related topic, issues involved in the personal exposure monitoring of employees working with binders were reviewed by J. Elwood, Ashland Chemical, Inc.

Such monitoring involves taking samples of airborne chemicals in an employee's breathing zone while he performs his job. In foundries, these workers include the resin mix, coldbox or nobake, machine and shakeout operators, and people involved with pouring, molding and maintenance.

Foundries should conduct personal exposure monitoring because OSHA requires it in most cases and because "we should all be concerned with the health of our employees," Elwood said.

What substances should be monitored? "This is where you have to stop thinking in general terms and get specific," he said. "For example, if you are conducting a survey of a coldbox making area, you should consider the items that an employee could come in contact with from the process."

Eliminating fugitive emissions from coreless induction furnaces was discussed in a paper by R. Youmans, Modern Equipment Co., and H. Rachner, DR. Kuettner Gmbh, Essen, Germany.

The popularity of medium-frequency coreless melters in Europe has triggered the use of a special close-capture furnace system to trap fumes. Since most U.S. coreless melting furnaces don't contain such a system, the European applications should be studied for use in America, the authors said.