Wakefield Hospital in Newtown is now providing medical masks to everyone who enters the facilities, and will not permit visitors with cotton or home-made creations.
"We're happy to provide surgical masks for those coming in with cloth masks, mostly because we don't know when they last washed them or how often they change them," she said.
"A lot of people tend to stuff their mask into their pocket and it stays there."
"And some were coming in with homemade masks that really weren't appropriate."
She said the change in guidelines was not based on scientific findings, but more on observations they had made.
"Just to get the consistency and make sure we felt there was adequate mask fitting, we thought it would be better to be consistent and just offer everybody surgical masks."
She said few people now tried to enter the hospital with a cotton or homemade mask.
In the mask-wearing guidelines provided on their website, the Ministry of Health says non-medical masks "do not necessarily conform to medical standards" and are therefore not used in medical settings.
The guidance provided by the Capital and Coast DHB on its website states medical masks are also to be used by visitors to Wellington and Hutt Valley hospitals.
"Medical masks provide a higher level of protection from Covid-19 and visitors are asked to wear one while in our hospitals," it reads.
"Medical masks will be provided at the entrances to our hospitals."
A CCDHB spokesman said the requirement for Wellington and Hutt Valley hospitals is not new and has not changed.