In the fiberglass reinforced plastics (FRP) industry, selecting the right ventilation technology to meet OSHA’s styrene emission requirements means finding – as one manufacturer states it – a system that delivers the right amount of air, in the right location, in the right quantity for the right amount of time.
But today’s state-of-the-art systems go far beyond simple air delivery. These advanced systems incorporate digital controls and energy saving heat recovery technology to not only reduce emissions and control dust from grinding operations, but also provide the worker with the ideal tem- perature for comfort and the process too.
These ventilation systems are so sophisticated and energy efficient, in fact, that they have turned what is traditionally the least desirable work area in a plant into a show room.
Compliance All manufacturers and fabricators must comply with EPA and OSHA reg- ulations as well as similar State regulatory authorities regarding the emis- sion of styrene, which is released in the plant work space and into the environment during the manufacturing process.
In the United States, OSHA PEL (permissible exposure levels) require- ments for styrene require that the breathing zone within the workplace average less than 50 ppm (parts per million) over an 8 hour period.
However, with so many regulatory agencies the rules can change in a hurry. Canadian fiberglass manufacturer Structural Composite Technology discovered, to its surprise, that the provincial government in Winnipeg, Manitoba had tightened requirements to a remarkably low 20 ppm. This was far below the 50 ppm in the U.S. and other parts of Canada and represented a more than 40% reduction from previous limits.
“Here in Manitoba, if a plant averages over 20 ppm, the workers must wear a respirator, when if you were in North Dakota – just south of us – you didn’t have to,” says John Zadro, president of Structural Composite Technology. “And if you were in Ontario or Alberta or Saskatchewan, they didn’t have to either.”
To meet these requirements, Zadro installed a state-of-the-art ventilation system when the company moved to a new, larger facility in November of 2007.
FRP-specific system or HVAC? For manufacturers like Zadro, the first question is where to look. Typically, ventilation systems have been designed and constructed by general HVAC contractors. However, these systems are not designed specifically for the needs of FRP manufacturers.
According to Zadro, general mechanical contractors lacked the knowl- edge of the fiberglass process and were essentially “learning on the job.” As a result, he selected a system from Frees Inc. (Shreveport, LA), a spe- cialist in ventilation systems for the fiberglass industry for over two decades. He was aware of the company because of its regular presence at industry trade shows.
“Frees not only had the engineering and the science, but they also had the
expertise and experience on the fiberglass side,” says Zadro.
Owen Maxwell, vice president of product development of offshore fish- ing boat manufacturer Regulator Marine, also selected Frees Inc. because of its in-depth knowledge of the industry.
“I was impressed by their overall knowledge of the open mold fiberglass industry,” says Maxwell. “They had been in and out of every major boat builder’s shop so they had seen what was working and what was not working,” says Maxwell.
Maxwell briefly considered other options, including HVAC contractors, when the company moved to a new plant. “They were learning as they were building these systems and some worked and some didn’t. We just didn’t want to be an experiment,” explains Maxwell.
Dilution ventilation versus directed air flow Most ventilation systems depend upon a methodology called dilution ventilation in an attempt to meet OSHA’s PEL requirements. The basic premise is to calculate and bring in enough fresh air to dilute the styrene levels to the required levels.
Unfortunately, dilution ventilation typically demands a tremendous vol- ume of outside air that must be brought in, heated to 70-75 degrees and then exhausted. Furthermore, if the worker is in a concentrated emis- sions zone, it is difficult to get the air to a specific spot using this tech- nique.
According to Zadro, the system he installed from Frees Inc., is not based on dilution ventilation, but is instead a directed air flow system designed
to ventilate the breathing zone of the worker, not the entire building.
The directed air flow system is a proprietary solution that can focus air in a controlled envelope that moves across the breathing zone and then “stops” (to prevent roll back and re-contamination of the work area), is captured, and then removed from the area. The contaminated air is forced out high enough for dispersion or routed through an end of stack (EOS) control as mandated by the user’s emission permit.
“There really is an art to how the system controls this air envelope,” explains Zadro. “The analogy is like blowing air around a lit candle, get- ting rid of the smoke, while not affecting the flame. With this system, our shop is regularly less than 20 ppm.”