Cooking oil: Smells like food to animal and insect visitors. It can also upset the compost's moisture balance.
Wet paper: In general, recyclers take a pass on paper items that have been exposed to water. The fibers may be damaged, and there are contamination risks.
Tires: Some states require a separate disposal of tires and collect a fee at the point of sale for that purpose. Therefore if you have replaced your old tire and decided to recycle it on your own to not let it go waste, give up the idea! Simply hand it over the company people you bought it from.
Meat products: This includes bones, blood, fish and animal fats. This is another pest magnet.
Milk products: Refrain from composting milk, cheese, yogurt and cream. While they'll certainly degrade, they are attractive to pests as well.
Stubborn garden plants: Dandelions, ivy and kudzu are examples of plants or weeds which will probably regard your compost heap as a great place to grow, rather than decompose.
Napkins and paper towels: Recycling is discouraged because of what they may have absorbed. Consider composting them.
Drinks cartons – Although some manufacturers have begun producing recyclable juice and milk containers, these will be specially marked. The rest are not suitable for any reprocessing.
Walnuts: You might be surprised but walnuts contain Juglone, a natural aromatic compound toxic to some plants. Therefore never compost them.
Batteries: These are generally handled separately from both regular trash and curbside recycling.
So next time you’re on a spree to reduce the curbside trash, do not mistakenly bring back these things to re-cycle or compost. In your half knowledge, you might just be harming the environment rather than saving it!