UK Technical Process Safety Forum (formally UK Chemical Reaction Hazards Forum)
 |  Previous |  Home |  Next |  SiteMap |
ICRA Label
Safe Surf
Miltronic DHTML menu
Creative Commons License

The Incident

Phosphorous oxychloride was being added slowly in small portions from pressure equalizing dropping funnels to a set of six reaction mixtures containing a substituted isoquinoline-N-oxide in dichloromethane.  After about 20% of the addition had been made the operator handed over to a colleague in order to take a break. Shortly after the relief operator restarted the operation one of the reaction mixtures began to froth.  Subsequently it climbed out of the condenser and was ejected from the vessel.

The Investigation

It was apparent that the two operators were doing something different.  Further investigation deduced that operator two was adding in bigger (& and less often) portions than operator one.


Lessons Learnt

Even minor process changes should always be reviewed by the appropriate team to make sure that the change will not cause any problems. In this case addition as a continuous slow stream was recommended for future production.

Back to Top