‘NR’ stands for ‘Not Recommended’. HOWEVER, it is worth noting that most chemical compatibility guides (ours included) are based on a one-year immersion test. In other words, the material being tested is completely immersed in the chemical in question. After one year, the material is removed and checked for any degradation. Needless to say, a spill response product is not going to be exposed to a chemical for a year. So it’s possible that the spill berm will be effective against a spill of a chemical that is listed as ‘NR’. The best way to know for sure is to test for yourself. Please contact our customer service team and they will be able to send you a no-charge sample.