"P labs have increased in frequency and it's a matter of making it safe for those people that follow on [in the raids]," Mr O'Leary said.
"It's pretty well known that people who dabble with the chemicals also tend to be armed."
The Hawke's Bay AOS has 16 members. There are no female members as a woman who was in the squad has recently left to have a baby.
Members ranged from junior officers in the police for just five years to those with more than 30 years of policing. Members were chosen through a demanding national selection programme.
"It's not just a matter of being physically competent for the role. It's very demanding physically and psychologically," Mr O'Leary said.
The Hawke's Bay AOS had attended a steady number of callouts in the past three years and was one of the busier provincial squads in the country.
Callout numbers had been rising due to policy changes and the 2009 Napier siege, which "changed the way we do our business", Mr O'Leary said.
The squads were established in 1964, after the fatal shooting of four police officers in incidents in Lower Hutt and Waitakere.
There are now 17 squads, covering all main centres.
The New Zealand Police website says the basic methods of operating for the AOS is to cordon, contain and appeal to armed offenders.
Police say the tactics are successful in most incidents, which are resolved without the use of force.
The AOS is also used for some pre-planned operations where a high risk is perceived, including large cash escorts and assisting other police with search warrants.
The squads are supported by negotiation teams and specially trained police dogs and handlers.
-APNZ
