January 2019 SPRAY 31
The magnitude of ΔG is determined by the:
• Formula or contaminant water pH
• Types of package metal
• Formula/package surface tension
• Chemical activity for each electrochemically active (ECA) ion
and molecule in a formula
• Surface condition of the spray package metal or metal foil
(e.g., un-coated, coated or laminated)
Figure 2: Possible forms of corrosion for laminated aluminum foil and aerosol valves.
Continued on next page