Shoppers are being encouraged to dob in retailers who supply single-use plastic bags, with fines for their use now in effect.

Key points: Small business have had six months to prepare for the plastic bag ban, which will now result in fines

Small business have had six months to prepare for the plastic bag ban, which will now result in fines The Government says there has been strong consumer support for the ban

The Government says there has been strong consumer support for the ban About 225 million lightweight plastic bags have been saved from entering landfill

The WA Government's ban on plastic bags began on July 1 last year, but small businesses were given six months to prepare.

Fines of up to $5,000 apply to all retailers from January 1.

In the months leading up to the ban, retailers and consumers expressed concern with how it would be handled.

After it was implemented, the union representing retail and fast food workers, the SDA, reported staff were subjected to complaints and abuse from customers for failing to provide bags.

But Acting Environment Minister Simone McGurk said the WA community had now largely embraced the ban, and she expected that to continue.

She said the ban had already made a significant difference.

Simone McGurk is urging consumers to do their part by having reusable bags on hand. ( ABC News: Rebecca Carmody )

"Six months ago the government introduced a ban on plastic bags, and there's been huge support for that," Ms McGurk said.

"Not only because it's important for the environment, but people also want to know what they can do to stop the littering of bags, and particularly the impact on our oceans.

"Since July 1, 2018, we have stopped around 225 million lightweight plastic bags ending up in landfill, or worse still in our oceans."

Prosecution and fines on the cards

Shoppers are being urged to report noncompliant retailers to the National Retail Association.

The ban includes lightweight plastic bags, including those that are compostable, degradable or biodegradable. ( ABC Radio Adelaide: Malcolm Sutton )

The Department of Water and Environmental Regulation will also follow up reports and conduct spot checks on businesses.

"We're hoping that it will be a carrot approach rather than a stick," Ms McGurk said.

"We will be working with the Retailers Association to make sure retailers and all outlets understand this is a positive campaign and we want them to come on board."

Plastic bag suppliers and manufacturers who provide misleading information when selling bags to retailers can also be prosecuted and fined.

The ban applies to all lightweight plastic bags, including those considered biodegradable or compostable, with a thickness of 35 microns or less.

Consumers encouraged to take active role

Ms McGurk said consumers could do their part to help.

"We've been really heartened by the amount of public support for the ban.

"I'm sure with a bit of time we will all get used to it and our environment will be better off as a result.

"We know other states and places where there's been a ban in place there has been a period of adjustment. Once people understand the rules the adjustment is made and people get on with business as usual.

"You can help by remembering to take your own reusable bags when you go shopping," she said.

"So be prepared. Always have your reusable bags on hand and remember to take them everywhere you go.

"Whether you're picking up milk from the deli, bread from the bakery or takeaway food from your favourite restaurant."