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Unintended sulphur pollution

Written by Administrator
Friday, 01 May 2009 09:14

Many years ago, a user phoned us to ask whether penetrant and non-aqueous wet developer (NAWD) with this and that batch numbers were still "valid". By the batch numbers we answered that the "use before" date was well behind us. The user, a large customer, told us he had about twenty 10-liter (2.66 US gal) cans of unused penetrant and non-aqueous wet developer.

"Could we take them back?" as the customer did not know how to get rid of them, we agreed:
"Please send them back transport prepaid".

On arrival, our surprise was ... big!

On the pallet we saw twenty 10-liter cans with labels of developer for radiographic films. Disbelieving we opened the cans ... which contained a colour contrast penetrant and a non-aqueous developer. Well ... but these products were used on nuclear parts and the prime required that every batch came with a certificate of analysis stating less than 200 ppm (0.02%) in sulphur, among other elements.
Do you see the problem? Developer for radiographic films contains potassium sulfite, i.e. a chemical high in ... sulphur!!

That means products such as penetrant and NAWD thoroughly controlled for sulphur content had been poured in cans where chemicals high in sulphur were stored. Who can prove whether these cans were really cleaned before being replenished with penetrant materials? Which cleaner was used? Were any traces of the original developer and/or cleaner still in the cans when replenished with penetrant materials? What about the analysis result for sulphur content if a sample had been taken out from one of these cans?

This example is not unique.
One of our companies had to fight for several months for a similar problem, this time about chlorine content. A random check by a very important audit company of a sample of a cleaner taken from a drum in a subcontractor's plant led to an unusually high level of chlorine detected, far above the 200 ppm acceptable limit. The cleaner's supplier was immediately accused of wrongdoing! But in fact the sample had been taken in uncontrolled conditions: not from the supplier's drum, there was no traceability as per the batch number, no one was sure of which chemicals could have been mixed in the drum. But several months and several harsh meetings were necessary to clear the supplier!

The lesson: preferably use the original cans as supplied by the supplier. If any transfer is nevertheless needed, be sure the new can is really completely free from traces of ANY chemical, report on a label all the information from the original label: product reference, batch number, "use before" date, risk and safety phrases/pictograms, the name of the product (for instance: colour contrast penetrant) as the product reference is not enough to know what the product may be used to.

In the '60s a UK Company had a motto: "For every surface treatment problem, there is a product xxxxxx" (trademark we do not display).

Engineers and Commercial people in this Company had made a "translation": "With every surface treatment product xxxxxx (trademark we do not display), there is a problem".

This anecdote is there only to remind everyone that problems met in workshops may be due to the suppliers/manufacturers as well as to the users.

Our idea in these documents is NOT to target anyone, but on the contrary to bring to your knowledge some interesting cases which may prevent you to duplicate the same mistakes while performing Penetrant Testing (PT) or Magnetic Testing (MT).

All the ministories you will read are TRUE. We think they will be helpful:
• First as examples of specific technical --or non-technical-- requirements or peculiar problems.
• Second to let you see that the problems do not always come where you think they should come from.
• Third so that users feel free to ask for help from people (the experts) who may know more than they do.

Last Updated ( Friday, 01 May 2009 00:00 )