A new report from Minneapolis-based General Mills highlights packaging-related initiatives among the company’s efforts to be a good corporate citizen.

In its “2010 Corporate Social Responsibility” report, General Mills indicates progress on its five-year goals to reduce its environmental impact. Among these are ways to trim waste and otherwise reduce the environmental footprint of its packaging.

One case study example noted that Betty Crocker Warm Delights desserts feature new bowls that contain 40% less plastic, perform better in the microwave and cost less to make. It’s an additional example of measures taken by General Mills that have helped reduce its solid waste generation rate by 24.5% since 2005, far surpassing its goal of 15%.

The product’s previous bowls were made entirely of polypropylene, which is sourced from petroleum. The new bowls contain 40% calcium carbonate, a material that occurs naturally in the form of chalk or limestone. Aside from a slightly less glossy finish, the bowls look the same. “Calcium carbonate is safe, in abundant supply throughout the world, and does not impact the recyclability of the finished bowl,” says Angie Brown, the General Mills packaging engineer who worked with a supplier to develop the new packaging. “It’s widely used in industries such as construction, pharmaceuticals and agriculture, but this is one of the first applications in retail food packaging.”

Product line managers were pleased to discover that it’s just as sturdy as the earlier bowl and performs slightly better in the microwave. The new bowls will reduce plastic use by 300,000 pounds per year and save the company nearly $500,000 a year in packaging costs.