It’s the topping of every great sundae, and can bring a smile to just about anyone’s face.

But a law that went into effect last November is causing confusion and controversy when it comes to who can buy whipped cream in New York.

Some supermarket chains interpreted it as no one under 21 could buy whipped cream because of the propellant used to dispense it from the can.

The law — S.2819-A — targets whipped cream chargers, specifically the cartridge filled with nitrous oxide used to propel whipped cream out of a can.

As of last November, You have to be 21 to purchase a charger. Penalties range from $250 to $500 per violation.

State Sen. Joseph Addabo of Queens sponsored the bill to keep young people from abusing the nitrous oxide to get high, commonly known as doing whippets.

Dr. Abraham Bartell has worked as a child psychiatrist for Westchester Medical Center for 25 years.

"I think the intention behind the legislation is spot on. At the end of the day, the greatest at-risk population is between 15 and 18, so preventing the sale, decreasing the accessibility of the nitrous oxide, regardless of what form, makes sense," said Bartell.

The confusion and controversy came with the implementation of the law. Grocery and convenience stores recently started restricting whipped cream sales to people 21 and over.

In a statement to Spectrum News 1, Kent Sopris, the president of the New York Association of Convenience Stores, said, “There was confusion on our part as to whether the cartridges within cans of whipped cream were included under the law. Out of an abundance of caution, I advised my members, and some chose to act on their own, to begin asking for ID. After conversations with the Senate sponsor and after a couple of statements he issued, NYACS is comfortable with the law and does not believe it covers whipped cream cans. I advised my members they do not need to ID.”

Bartell said the use of whippets in adolescents and young adults isn’t new.

"Nitrous oxide is probably the single most inhaled, abused substance in the 15 to 18-year-old range because it's so available," said Bartell. "It depletes a vitamin in your body called vitamin B12 that’s used to build and maintain the health of how nerve cells work in your brain, so long-term use compromises the health and the function of those nerve cells."

Bartell said parents should keep a closer eye on their kids if they see more whipped cream than usual being bought, or multiple canisters in the garbage.

And if your child is complaining of residual effects of whippet use, like numbness in the face, hands or arms, Bartell said you should have them medically evaluated.