Multiple pure sub for same CAS#

[former_member215519]

Hi EHS experts,

We have some scenario that we need to create multiple pure subs for the same CAS# due to their different GHS classiciation or OEL according to the physical state liquid vs solid.

Our current practice, not very good one, is we will manually modify the related pure sub in the standard composition. For example if the final product is solid, and if we find the breakdown in standard composition is using the liquid version of the pure sub, we will do a replacement. So far so good, but it becomes kind of nightmare when we will have more and more such cases in the system. We are using 3E expert rules, and normally standard composition is calculated from exact composition based on product, with this manual edit, we feel we cannot easy update our composition easily in the long run and have to keep track of those changes offline.

Do you have similar scenario in your company? It'll be great if you can share some experience how you handle that your side. Our way to change standard composition looks bit ugly and by force. Is it better we change data one level up, that's exact composition based on product? But to make that happen, I am sure we will need to have a lot of data exercise, and need to fix/correct the data from bottom to top, like first need to have two raw sub to represent different physical state and so on. Not easy...

Please advise if you have any good idea on this topic. Thanks a lot.

[christoph_bergemann]

Hello

depending on your chemical portfolio... i would assume that you might need to duplicate may be 50 CAS numbers, but could be clearly more than that. Because of many new regulations.. as well the "polymer" story will get more complex. Example: there is one CAS number for "polyethylene"... but in reality: you need more "PURE_SUBs" for some polymers. EU is preparing the next REACh initiative; it is assumed: for polymer: it will get more worse and you need to "duplicate" a lot (but we need to wait until the final regulation is ready).

And i am sorry: there is no other option than to "duplicate". One example (and this was discussed here as well) is "HCL" (hydrochloric acid). We need here a differentiation: do we talk about a HCL solution in water or do we talk about a "gas"? And there are more than this example to consider. The same is true for "H2SO4" (sulfuric acid) and many other examples. Because of different hazard by councetration: you might need more puresubs

C.B.

PS: one "simple" additional example is "Carbon". Here you have the modification "diamant" and "graphite". Clearly different regard the hazards; same is true for "phosphor" (and many other examples9

[christoph_bergemann]

Hello

your case is 100% normal. from my point of view: it is "daily business". There are a huge number of needs/demands/reasons to prepare more than one PURE_SUB for the same "LIST_SUB" and therefore the same "CAS" number

Luckily: the need is differentiated by "regulation". And therefore by change of the data model (how you populate the "Compositions" and use the rules): an easy solution is possible.

BUT from expert point of view IT IS NOT EASY. The challenge is: if you maintain a "composition" and you select a "PURE_SUB" (or try to do so) you do not have many selection options (e.g. number, name etc.). So e.g. the "NAME" of the PURE_SUB is one differentiating factor. The details are VERY tricky !!

C.B.

[former_member215519]

Thanks C.B. for your comments. Yes, that's what we are currently doing, by naming the same CAS# pure subs with some different names. We tried to avoid that as much as possible, but sometimes we will have to create more than one pure sub due to different GHS classifications and so on. It sounds like that's something we cannot avoid eventually, and the data work is necessary. We need to tick and untick some of those data during the OCC load to list sub and even create more than one list sub for some cases...

Just hope we will have a better way and that's why I asked this in the forum and wanted to get some ideas from your experts. Thanks.

[satya11719]

Hello John

You can create custom logic to bring the accurate pure subs in the composition, having multiple Pure substances is not standard and rules will get confused between the different pure subs with same cas numbers may you can add an identifier to specify the pure sub which you need to add in the standard composition to avoid the confusion in the logic

Best

Satya