Thanks for that Rodgerc - in a distant previous life, I supplied ethylene diamine (and other neutralising and filming amines) to oil refineries and many other industrial processes.
I’m very aware of the circumstances at Mobil Altona and what led to the amine ending up in Avgas back in the ‘90s. Fortunately for me, it was a competitors product, but ultimately there was no fault by the supplier. The root cause was the operation of the alkylation plant being unstable leading to acid carryover into downstream processes. The neutralising amine is routinely dosed to these downstream processes to neutralise the acid and thereby limit corrosion. The suppliers responsibility is to monitor the pH and adjust the amine dose accordingly. The more acid carryover, the lower the pH in the downstream processes- keep cranking up the amine dose. The suppliers performance was measured by the corrosion rate. This led to a massive overdose of amine. Of course, Mobil may have a different opinion - it’s usually the supplier that cops it.
Anyhow, getting a bit off track. Of course we are largely relying on overseas refineries these days, with the exception of Avgas which predominantly is produced at Viva in Geelong-that is until they had a fire in their alkylation unit.