Drug lab raided in Sydney's west

A clandestine ice lab has been discovered in the garage of a home in Sydney's west.

Three men have been arrested over the drug lab, discovered by police in a raid at Merrylands on Wednesday night.

Detectives also seized a loaded Colt .45 calibre pistol.

A 40-year-old man was treated at Westmead Hospital for chemical irritation to his eyes before being charged with manufacturing a commercial quantity of methylamphetamine and possessing an unauthorised pistol.

He was refused bail and is expected to face Parramatta Local Court on Friday.

Two other men, aged 43 and 25 have been released pending further inquiries.