That's an excellent and practical question! As someone who's dealt with messy outdoor bins for years, I completely understand the concern. You want to keep them clean and sanitary without damaging the material.
The good news is that most quality outdoor trash bins, especially those made from high-density polyethylene (HDPE) or other durable plastics, are quite resistant to common household cleaning chemicals. They're designed to withstand the elements, which includes resistance to many acidic or alkaline substances found in cleaners.
For routine cleaning, a solution of mild dish soap and warm water is perfectly safe and effective for removing grime. Bleach solutions (diluted properly, about 1 part bleach to 10 parts water) are generally safe for disinfecting and combating odors, but it's best to rinse thoroughly afterward. Similarly, all-purpose cleaners, white vinegar solutions, and baking soda paste are typically fine for tackling stains and deodorizing.
However, I'd recommend avoiding harsh chemicals like undiluted bleach, concentrated acids (like some toilet bowl cleaners), strong solvents (like acetone or paint thinner), or abrasive cleaners with gritty scrubbing particles. These can potentially dull the surface gloss, cause micro-cracks, or weaken the plastic over time, especially with repeated use.
The key is always to check your bin's manufacturer recommendations if available. When in doubt, do a spot test on a small, inconspicuous area first. Rinse the bin thoroughly after any chemical cleaning to remove residue. This balance of regular cleaning with appropriate products will keep your bins hygienic and extend their lifespan for many seasons.