Rubber deterioration in 1 year old EF 2x III?

Has anyone else seen this? It looks like very premature oxidation of the rubber ring.

 

The white has also recently appeared on the outside of old EF 25mm extension tubes hard black cases. I am really afraid there is some nasty chemical vapor in the air. There is lots of expensive equipment in this room.

 

Any ideas?

Just noticed an older Canon EF 1.4x II does not have the film on the same part.

Has anyone else seen this? It looks like very premature oxidation of the rubber ring.

 

My first thought was mould or similar, requiring moisture and also oxygen.

 

Please describe the storage environment - that may provide better clues.

 

Is the area/room where the equipment is stored dry (i.e little humidity); is there good air flow around the equipment; is the equipment stored against an interior and not an exterior building wall; is the equipment stored in cupboard made of metal and not wood; is the equipment kept in open storage and not in lens bags or camera cases?

 

WW

Just a wooden shelf in an office. The humidity is normal. Is it not degradation of the rubber by some oxidation?

. . . Is it not degradation of the rubber by some oxidation?

 

I don't know, but it seems more likely than mould, given your response.

 

It seems that you main concern is that chemical vapour is in the room: and I think that you must have some reason for that concern, so if that was really a serious comment, then I suggest having your office air checked by experts.

 

Regarding the Tele-extenders – I have two: both are MkII versions they are about 7 years old (stored in metal camera cabinets in my dry and airy office). I had a close look at both of them and there is minor amount of what appears to be oxidization, similar to your picture.

 

This was easily was removed when I rubbed my finger over the area.

 

Perhaps the MkIII versions have a different composition rubber which discolours more quickly.

 

I am not convinced that the discolouration means any (significant) 'deterioration' or will result in performance loss

 

WW

Okay thanks. I'll try cleaning it. There was a bottle of ethyl acetate in the closet that had ended up evaporating over a year. Having worked in a chem lab, I saw acid vapors quickly damage electrical components. However, there is no damage to the EX 1.4 II, so hopefully this is just an oddity that won't impact other parts. I appreciate the input!