SACRAMENTO, Calif.—At Paris fashion week this spring, designer Karl Lagerfeld stunned viewers with the fluffy, ice-age suits he presented for Chanel's fall line. The biggest surprise: every outfit in the show was made with fake fur.

In California, consumers face the same fuzzy confusion: A loophole in the federal law allows many fur products to go unlabeled, so consumers don't know if the soft trim on their jacket is made from synthetic products or raccoon dogs. That could change under legislation scheduled to be heard this week in the Assembly.

"I believe that people would think twice if they knew that they were wearing real animals," said bill author Assemblywoman Fiona Ma, D-San Francisco.

Those animals are raised in foreign factories that sell fur at low prices, Ma said. Because the fur price is kept so low, clothing manufacturers don't have to label their coats and sweaters as containing real fur.

Under current law, only garments that contain more than $150 worth of animal fur have to be labeled as containing real fur. Ma's bill would require that all garments containing fur are labeled with the type of animal and the country of origin.

Five other states have passed similar legislation.

Identifying the source of fur can be tricky. Ma this week showed off a jacket in her office that features a pink fur-trimmed hood that she said was made from a raccoon dog, a canine species from Asia. Because of the unnatural color and low price, a consumer may be fooled into thinking it's fake, Ma said.

Real fur garments also can cause problems for people with allergies, not to mention ethical objections. The cost of the raccoon dog fur lining the pink jacket is estimated at 25 cents, Ma said.

The Federal Trade Commission estimates that one in eight fur-trimmed garments lack a label explaining the source of the fur, Ma said.

"Knowing that a dog was killed for a piece of garment, I wouldn't want to do that," said Ma, who introduced the bill at the request of The Humane Society of the United States.

Ma's office knows of no opposition to the bill so far.