Be sure to check if you have the correct one. Remember that steam is another name for water and the steam cleaning of lines is very common in the process industry. Caustic is another common cleaner and caustic contains a high percentage of water also. This is the elastomer that is most often used in Rubber Bellows Seals. The problem is Ozone attack.
Ozone is produced by the sparking from electric motors, so it is a very common problem.
A typical shelf life for most Buna compounds would be one year. Chemical attack is usually recognized by a swollen and soft elastomer while high heat will produce a shrunken, hard one. Chemical attack of the elastomer will usually cause a seal failure within five to ten days. Look up the chemical in published O-Ring charts provided by all reputable seal companies. You will find a chart in the chart section of this web site Check to see if the plant has any experience with O-Rings, in this fluid, in another seal application.