The association's submission on the bill said police were often frustrated with the difficulty of keeping children out of potentially contaminated homes.
A law change was needed to help them do so.
"The current legislation makes it difficult to properly hold to account those responsible for the endangerment."
The Police Association is supported by Auckland lawyer Chloe Barker, who has studied the dangers of P labs to New Zealand children.
She said that while there was awareness of the meth epidemic, there was less focus on the damage being done to children.
Ms Barker told the Weekend Herald that while she didn't oppose the sentencing bill, she thought the emphasis was in the wrong place.
"It is a step in the right direction. For a long time children have been the forgotten victims of meth labs and the methamphetamine epidemic."
It was a little bit like having the ambulance at the bottom of the cliff, because if a prosecution was not successful in convicting offenders, then having a child present during the manufacture of the drugs would not even be an issue.
"A child living in a meth lab is inherently in danger and it is such a dangerous place for them to be that my feeling is it should be a criminal offence for someone to be manufacturing methamphetamine in the presence of a child or to know a child is present in a meth lab and not do anything about it.
Society should say strongly that children were important enough to have laws for such an offence.
"There can't be any doubt that New Zealand children are being damaged in those labs and there needs to be a strong reaction to it."
Labour MP and children's spokeswoman, Jacinda Ardern, said Labour had not yet decided its final position. If the aim of the bill was to increase sentence, the bill would do that.
"If this is about the longer-term care of the child and whether or not they were exposed to that kind of environment ... then it probably doesn't address that issue."
A spokeswoman for Justice Minister Judith Collins said the Government supported the sentiment of the bill but would wait for the select committee to report.
Numbers
• 94 secret P labs busted by police last year
• 45 children discovered in 27 labs