Amazon is threatening third-party sellers with fines for using excessive packaging for large items, in an effort to reduce waste, minimize shipping costs and ensure that customers can open boxes more easily. Third-party sellers who violate the rules can be fined $1.99 per order. The new fines, announced in a letter to sellers in September, were supposed to take effect on Aug. 1, giving sellers nearly one year to become compliant. However, Amazon is delaying implementing the rules until Sept. 3 because some sellers want Amazon to first certify their packaging as being acceptable. In the ramp up to the new rules, Amazon has been giving sellers a $1 per order credit to get them on board with the new shipping guidelines. The new rules in September only apply to items that are larger than 18 x 14 x 8 inches, or over 20 pounds. It's all part of Amazon's broader environmental push. Amazon revamped its own packaging in 2010 with its so-called Frustration-Free Packaging initiative, which aims to cut down on waste and ensure that customers can open packages without box cutters and scissors. It has also cleared some products to be shipped without extra packaging. Also as part of its environmental efforts, Amazon says it has avoided using 244,000 tons of packing materials over the past decade, or as many as 500 million boxes.