• Baby Wipes

  frequent cause of clogs and should always be thrown out in a wastebasket instead. even "flushable" wipes don't disintegrate the way toilet paper does, which will eventually cause plumbing issues.
• Bleach

  Bleach might be a part of your regular toilet cleaning routine, but bleach is actually too harsh a chemical for your toilet and septic system, you can get the stains in your toilet out by using vinegar instead.
• Cigarette Butts

  contain toxic chemicals, flushing cigarettes down the drain adds those chemicals to the water. Not to mention, it's a huge waste of water when you can simply throw them out properly. And, cigarette butts also cause clogs
• Cooking Grease

  You shouldn't pour cooking grease down the drain, it should make sense that the same goes for your toilet. Cooking grease congeals when it cools, it'll do the same in your pipes
• condoms

  not designed to break down in water, flushing them will cause clogs in toilets and septic tanks
• Dental Floss

  can clog your pipes, it can also cause environmental damage, floss basically turns into a net when flushed, catching and holding onto other debris — it can even wrap around parts of your septic system and burn out the motor.
• Diapers

  You shouldn't even be able to flush a diaper, but on the off-chance that you can and do, it'll expand and get caught in your pipes. That's what diaper pails are for!
• Fish

  people flush pet fish when they die, but this is actually not a good idea — they don't break down in water, flushing a fish or anything like it down the toilet can cause a clog. Stick to a proper burial instead
• Food

  food that hasn't been digested will cause problems for your plumbing. Sure, it's biodegradable and will break down eventually, but it will clog until that happens
• Gum

  doesn't break down in water, either. Plus, it's sticky and can adhere to the inside of your pipes and cause a clog. always throw gum out in the waste basket
• Hair

  forms a sort of net when you flush it and gets caught on basically everything — plus, it floats, and never dissolves in water no matter how long it's in there
• Kitty Litter

  may claim to be flushable, but toilets don't use enough water to move the litter along your pipes — and all it does is add more things to the water that make it harder to purify. Cat waste from the litter box should also not be flushed, because the litter dehydrates the waste and toilets are meant to flush water soluble waste.
• Medication

  don't flush them — toilet water doesn't break them down properly, medication causes toxic environmental effects
• Menstrual Products

  should never be flushed down the toilet. Because they're products that are meant to absorb water, not break down in it, they only expand when you flush them — and that's no good for your plumbing.
• Paper Towels & Tissues

  aren't all that different from toilet paper, but they're not designed to break down the way toilet paper does. In the event that you need to use paper towels or tissues in place of toilet paper for any reason, put them in a wastebasket instead.
• Q-Tips & Cotton Pads

  definitely not safe to flush — they don't break down the way toilet paper (even cotton toilet paper) does, they clump together in your pipes and cause problems.

when plumbers are called for any of the above, it is expensive