Actually, it's the rubber attachable tips, and they smell like off-gassing plastic, and it really bothers me. I've tried cleaning them with rubbing alcohol and soap and water.
Off-gassing smells should be taken seriously and are indicative of airborne pollutants. They can be VERY toxic!!
"One of the main chemicals used to produce plastics is bisphenol A, or BPA, an endocrine disruptor that is prevalent in a vast number of widely used products, not least of which are plastic food and beverage bottles and the lining of metal cans. Heat, repeated washing, acidity, and alkalinity cause the BPA in plastics to leach into our food and beverages. Further, BPA leaches into our groundwater from all the plastic sitting in landfills. And of course we ingest BPA from all the fish we eat that has previously ingested all that plastic floating around in the ocean.
In one study, the Centers for Disease Control found 95 percent of urine samples contained some amount of BPA. It’s in our blood, our amniotic fluid, our breast milk. Small children are most at risk because they put everything in their mouths, they breathe and drink more, relative to their size, and they excrete waste more slowly."