The bill is open for submissions and Brown said while they were encouraging the organisations to have a say it was important for the public as well.
McClay said the current law made it appear synthetics were "not as serious" as other drugs.
"We know, there's harm that can be caused by these drugs. A longer punishment could be a deterrent to dealers, when the risk is made greater."
McClay said while the bill itself tightens the sentencing for manufacture and supply there was always more that could be done.
"We have heard today that people are substituting drugs based on availability, on price.
"There are people who aren't taking them, just making money and creating harm.
"It's about finding a balance in policing, enforcement and then the treatment of the harm that is caused to people and their families."
Rotorua police area prevention manager Inspector Brendon Keenan said it had been a "good discussion".
"My main message to them is that our biggest problems are around family violence, youth offending, organised crime and harder drugs, rather than the synthetics."
Keenan said Rotorua had issues with synthetics in the past and they were always concerned about anything creating community harm.
"People are taking stuff and they don't even know what's in it. When we're turning up to a job we have no idea how they could react.
"The bottom line is to target those who are supplying, but our concern is really those being harmed."
Keenan said spotting those who are supplying the drugs can be a challenge as they often don't know what's in them and a lot of the chemicals used in production are legal.
Submissions on the bill are open until May 4.