Cat Litter: Is It 'Green' If You Flush It?

Flushable cat litter is sometimes marketed as green, but here's the rest of the story: It's not if you flush it down the toilet.

That's right. Don't flush "flushable" cat litter, scientists say. Double bag it and send it to a sanitary landfill.

By flushing cat poop, pet owners unwittingly may contribute to the deaths of Hawaiian monk seals and California sea otters and otherwise spread a hardy parasite linked to cats. As a result, a California law actually requires kitty litter to bear warnings such as this excerpt: "Please do not flush cat litter in toilets or dispose of it outdoors in gutters or storm drains."

Here's the deal: What flushes down the toilet or languishes outdoors can eventually reach waterways and oceans, "putting wildlife at risk for infection, including sea otters," states the Companion Animal Parasite Council (see here -- (PDF). Only cats and other members of the cat family shed in their feces a parasite that can live for months or years in soil and can be carried long distances in water.

So much for a "green" flushable litter. Researchers have found the cat parasite in question, Toxoplasma gondii, in dolphins and a humpback whale. So while flushable kitty litter is environmentally friendly in terms of being made of, say, recycled newspaper instead of clay, which must be mined from land, it isn't eco-friendly in terms of spreading a harmful parasite when flushed.

"There is no cat litter that can inactivate Toxoplasma," Patricia Conrad, DVM, a parasitology professor and co-director of University of California Global Health Institute's One Health Center, told me via email. On a hunt to figure out a way to kill the parasite's eggs, she and her colleagues conducted a series of experiments. No luck.

"They are amazingly tough," Dr. Conrad says. The experiments "really convinced us" that the procedures being used at most sewage treatment plants to treat wastewater from toilets "will not reliably kill" the parasite's eggs. (The exception is if the sewage treatment plant is able to filter out particles smaller than 10 microns.)

What is a green cat lover to do?

• Don't compost cat litter. Compost doesn't get hot enough to kill the parasite's eggs, Dr. Conrad says.

• Don't bury cat poop. Toxoplasma eggs can stay alive in soil for months to years depending on the temperature and humidity. So they can percolate down to the groundwater, where they could contaminate drinking water used by humans or animals, Dr. Conrad cautions, or flow into receiving water bodies and eventually reach coastal areas where marine mammals could become infected.

• Don't assume that your cat doesn't carry the parasite just because he lives indoors. While an indoor cat has a much lower risk, Dr. Conrad says "the risk is not zero."

• Do bag up cat poop and send it to a sanitary landfill. "We would like to reduce the burden on landfills," Dr. Conrad says, but "we don't yet have a good alternative."

finance investing business news economics news finance news