Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Seems to have lost their NSF certification

The original D250A cartridges are NSF certified. They also clearly state on the label that it removes lead, atrazine, and other VOCs. The NSF seal, as well as the claim for lead and atrazine removal are now gone. All it does is improve taste (chlorine removal). Until they get their NSF certification back, I would stay away from these.