Brown paper bags are compostable and you can use them for your organics recycling.
Certified compostable plastic bags are often carried in grocery stores, hardware stores, large retail stores and sometimes in garden stores and nurseries. You can also search online for "BPI compostable plastic bags." Compostable bags come in sizes including mini, standard, lawn and leaf, and sometimes larger for businesses.
Make sure any plastic bags that claim to be compostable carry the BPI compostable logo on both the box and the bags themselves. If buying bags online, check BPI’s website to verify they are certified compostable.