Cat litter options at supermarkets and discount retailers often include only clay-based product lines. Larger or specialty pet stores, however, carry alternatives. For example, one big-box pet store, with branches in Newbury Park, Oxnard, Camarillo and Ventura, carries cat litter products made from wheat, corn, pine, paper, walnut shells and silica gel.

The EcoAdvice website of Stanford University says more than 75 percent of all cat litters on the market are made from bentonite clay. While the silicate, aluminum, magnesium and iron in the clay make it effective at absorbing moisture and controlling odor, some people look for alternatives because bentonite comes from surface mines, mostly in Wyoming. Making cat litter from waste products, closer to home, has less impact on the environment.

Cat litter made from paper often comes from the waste fibers of newspaper recycling facilities; these are fibers too short to be made into new paper, but still effective at absorbing cat waste. Cat litter made from corn usually comes from ground-up cobs and rejected kernels handled by food processing operations. Walnut-based cat litter is made from shells. Compared to clay, recycled newspaper fibers are approximately 4 percent more expensive, wheat 10 percent more expensive, and corn 90 percent more expensive according to the Stanford site. Other alternatives are highly variable.

Silica gel, while not a recycled product, is another alternative. It is the same material you might find in little packets to keep items fresh or dry, carrying the warning “Do not eat.” Although it is expensive, on-line reviews claim it generates the least dust. It absorbs liquids, leaving solids to be scooped out. After a few weeks, when the silica is yellow from absorption, owners dump the crystals, scrub the box, and start over.

Two environmental claims made by alternative cat litters do not apply in Ventura County. Some brands label their litter “biodegradable” or “flushable.” The potential biodegradability of cat litter is irrelevant when there are no local compost facilities accepting the material, and backyard compost piles with cat litter could pose dangers to pregnant women or immune-compromised individuals, due to the pathogen Toxoplasma gondii, frequently carried by cats. Even if a pregnant woman does not touch a compost pile containing cat litter, there is a danger that t. gondii can spread to her; rats are attracted to cat feces and can spread the pathogen.

On the other hand, cat litter collected in plastic bags, placed in trash carts and buried in landfills is unlikely to degrade at all, regardless of its content.

As for the “flushable” claim, California Law (Assembly Bill 2485 of 1986) requires these brands of cat litter to also include a statement debunking their own claim. On legally compliant brands, usually in small print on the packaging, you will also find printed, “Please do not flush cat litter in toilets or dispose of it outdoors in gutters or storm drains.”

The state legislature instituted this requirement in a bill about sea otters. Researchers found that Toxoplasma gondii from “flushable” kitty litter passed through many wastewater treatment facilities and, even in minute amounts, harmed sea lions.

Using any type of kitty litter has advantages over letting your cats roam free to usethe neighborhood as their litter box. Cat feces poses health risks to people while on land and to marine life if it washes down storm drains.