Hot paa!!

[THL]

Just walked into the brewery to find the assistant brewer doing a hot PAA CIP! He had mixed up the PAA with the Caustic and was merrily going about his chores CIPing at 170F with double strength PAA. Ultimately I blame myself as I should have been overseeing him, but at the same time he really should have enough experience and knowledge now not to make such a simple mistake, having now worked for us for over six months.

Normally we would use PAA at around 70F, and I realise that at higher temperatures it can be damaging. I caught onto what had happened pretty quick, because of the smell, and rinsed out all the PAA immediately and then followed with the normal Caustic and then a Phosphoric cycle to help the stainless a little. I'm just wondering how worried I should be about any possible damage and if there is anything else I can do to reverse any damage that may have occurred. If any of you have any input on the matter it would be most appreciated.

Cheers,

Tom

[dick murton]

If he was using it this temperature then virtually all you will be recirculating is dilute acetic acid. The PAA will have broken down very rapidly. There should be no adverse effect on stainless, but it may have damaged seals due to the temporary extreme conditions as the PAA breaks down into oxygen and acetic acid. PAA helps retain the passivation of stainless, so I wouldn't worry on that particular front, but would have a good look at seals, and keep monitoring. It's possible any damage won't show up instantly, but you may have to replace a bit earlier than normal.

[THL]

If he was using it this temperature then virtually all you will be recirculating is dilute acetic acid. The PAA will have broken down very rapidly. There should be no adverse effect on stainless, but it may have damaged seals due to the temporary extreme conditions as the PAA breaks down into oxygen and acetic acid. PAA helps retain the passivation of stainless, so I wouldn't worry on that particular front, but would have a good look at seals, and keep monitoring. It's possible any damage won't show up instantly, but you may have to replace a bit earlier than normal.

Cheers Dick, that eases my mind.