Is It Septic Safe? A Plain Ingredient Guide

The short version

Chlorine bleach

Our answer: Go easy.

Occasional, measured bleach is fine for most systems. A Cornell Cooperative Extension fact sheet found that in normal household use, 97 to 99 percent of the sodium hypochlorite in bleach reacts with soils and stains before it ever reaches the tank. The concern is how often. University of Arizona Extension counts frequent use of detergents with bleach added as excessive. Save bleach for occasional jobs and measure it.

Oxygen bleach (sodium percarbonate)

Our answer: Normal use is fine.

University of Vermont Sea Grant lists oxidized bleaches among less hazardous choices than common household cleaners. Our Oxy Boost has one ingredient, sodium carbonate peroxyhydrate (sodium percarbonate), and is labeled septic-safe.

Borax

Our answer: Normal use is fine.

Cornell Cooperative Extension lists borax among cleaning products meant to be rinsed down the drain in normal use, and University of Vermont Sea Grant lists it among less hazardous choices. Use the amount on the box.

Quats (quaternary ammonium compounds)

Our answer: Go easy.

Quats are common in spray cleaners and pre-moistened wipes. On a label, look for names that end in "ammonium chloride," such as benzalkonium chloride. Research summarized by Sara Heger of the University of Minnesota Onsite Sewage Treatment Program found that quats can slow the microbes septic and wastewater systems rely on, even at a few milligrams per liter. Use them sparingly, and don't make them your everyday cleaner.

Vinegar

Our answer: Normal use is fine.

University of Vermont Sea Grant lists vinegar among less hazardous choices than common household cleaners. Use it the way you normally would and rinse. Curious how it compares with a probiotic cleaner? Read White Vinegar vs Probiotic Cleaners.

Baking soda

Our answer: Normal use is fine.

Cornell Cooperative Extension lists baking soda among cleaning products meant to be rinsed down the drain, and University of Vermont Sea Grant lists it among less hazardous choices. Baking soda (sodium bicarbonate) is in Flushy, Sinky and Septy.

Enzyme cleaners

Our answer: Normal use is fine.

Enzymes in a cleaner help break down food soils and residue on surfaces and in drains. Oregon State University Extension notes that a septic tank already contains the bacteria and enzymes it needs to break down waste, so an enzyme product is never a substitute for pumping. We found no extension guidance warning against enzyme cleaners in normal cleaning use. Looking for an "enzyme drain cleaner" for a clog? See chemical drain openers below; a clog needs a snake or a pro.

Probiotic cleaners

Our answer: Normal use is fine. Pumping comes first.

Probiotic cleaners include cultures such as Bacillus alongside the cleaning agents. Flushy and Sinky contain a probiotic Bacillus blend, and Septy contains active Bacillus spores. Here's what the experts say, plainly. University of Vermont Sea Grant says septic additives are not needed and that most won't harm a system. Oregon State University Extension says a healthy tank already has the bacteria it needs, notes that some biological additives may change the quality of treated wastewater, and suggests talking to a licensed septic professional before you add any additive. We agree that pumping and good habits come first. Think of a probiotic product as part of a routine, never as a replacement for a pump-out.

Chemical drain openers

Our answer: Keep it out.

EPA advises avoiding chemical drain openers and using boiling water or a drain snake instead. Oregon State University Extension adds that degreasers and drain cleaners can contaminate groundwater and damage soil structure. For routine sink and disposal cleaning (not clogs), Sinky uses baking soda, citric acid, a probiotic Bacillus blend and a plant-based surfactant.

Wipes

Our answer: Keep it out of the toilet.

EPA lists non-flushable wipes, such as baby wipes and other wet wipes, among things never to flush. University of Maryland Extension puts it simply: only flush toilet paper, and put wipes in the trash.

In-tank toilet tablets

Our answer: Go easy.

University of Arizona Extension advises skipping toilet bowl cleaners that release with every flush, and doing more scrubbing with less cleanser. Flushy is a pre-measured toilet bowl cleaner packet with baking soda, citric acid, a probiotic Bacillus blend and a plant-based surfactant.

Solvent-based septic additives

Our answer: Keep it out.

A Cornell Cooperative Extension fact sheet says solvent-based septic tank additives are not recommended, have no proven benefit and may harm the system. Read the label of any septic product before you buy it. Septy's four ingredients are baking soda, washing soda, salt and active Bacillus spores, with no solvents.

Frequently asked questions

Is bleach septic safe?

In normal amounts, now and then, yes for most systems. Frequent bleach use is what extension services warn about. Measure it and save it for occasional jobs.

Are enzyme cleaners septic safe?

In normal cleaning use, we found no extension guidance against them. They don't replace pumping, because the tank already has the enzymes it needs.

Are flushable wipes septic safe?

Keep all wipes out of the toilet. University of Maryland Extension's advice is to flush only toilet paper and put wipes in the trash.

Is vinegar safe for a septic system?

Yes in normal amounts. University of Vermont Sea Grant lists vinegar among less hazardous choices than common household cleaners.

What should I use on a clogged drain if I have a septic tank?

EPA suggests boiling water or a drain snake instead of a chemical drain opener. If that doesn't clear it, call a plumber.