Development of a push-pull ventilation system to control solder fume

Area of Science:

• Occupational Health and Safety
• Industrial Hygiene
• Environmental Engineering

Background:

• Hand soldering with rosin core solder wire is prevalent in electronics, producing aerosols linked to respiratory sensitization.
• Current control methods like local exhaust hoods and low-volume high-velocity (LVHV) systems are often inadequate for solder fume.
• A novel push-pull ventilation design was developed to address the limitations of existing solder fume control systems.

Purpose of the Study:

• To evaluate the capture efficiency of a new push-pull ventilation system for controlling solder fume.
• To compare the effectiveness of the push-pull system against existing in-house ventilation in electronics factories.
• To assess the impact of the ventilation systems on worker exposure to rosin-based solder flux fume.

Main Methods:

• Laboratory tests using nitrous oxide tracer gas to determine capture efficiency (>90% with push airflow).
• Field studies in five electronics factories comparing push-pull systems with existing ventilation.
• Measurement of personal exposure levels to rosin-based solder flux fume (total resin acids).

Main Results:

• The push-pull system demonstrated high capture efficiency in laboratory settings, particularly with active push airflow.
• In factories, the push-pull system provided more consistent control of solder fume than in-house systems, especially during high-volume soldering.
• Personal exposure levels were significantly reduced below the UK Maximum Exposure Limit (MEL) with the push-pull system, unlike existing methods.

Conclusions:

• The push-pull ventilation system offers a more effective and consistent solution for controlling inhalation exposure to rosin-based solder flux fume.
• Existing in-house ventilation systems in electronics factories were found to be relatively inefficient, particularly under higher soldering loads.
• The findings suggest a need for improved ventilation strategies to protect workers from respiratory risks associated with soldering operations.