Darwin has now officially banned the use of plastic bags.

As of the 1st September, Darwin has officially said "NO" to the use of lightweight, "checkout" style plastic bags. This means shoppers need to either bring their own bags, or grab environmentally friendly bags from the shop.

The following bags are not banned:

• Green bags (keep clean and re-use over 100 times);
• Biodegradable or compostable bags;
• Heavy retail bags;
• Paper bags;
• Barrier bags for fruit and vegetables.

"Remember, degradable bags are not the same as biodegradable bags," the Government said.

"Degradable bags will be banned as degradable plastics merely break down into smaller and smaller flakes, which continue to pollute for many years, whereas the bio-degradable bags biodegrade within 180 days under industrial composting conditions."

Territorians use about 40 million plastic bags each year. The plastic bag ban is part of the Government's $34 million climate change policy.