The federal trade commission ftc is starting to get tougher on packaging that claims to be biodegradable, telling kmart corp. And two other companies that such claims are &ldquofalse and unsubstantiated.&rdquo the ftc said kmart&rsquos american fare disposable plates cannot be labeled biodegradable because evidence does not exist that it will disappear quickly in a landfill condition. Two other companies tender corp. And its fresh bath moist wipes and dynae intl. And its lightload compressed dry towels &ndash also were cited by the ftc for misleading packaging that could not be considered biodegradable. According to the ftc&rsquos green guides, a package must degrade &ldquoin a reasonably short period of time after customary disposal&rdquo and scientific evidence must show that the package will completely break down. However, the evidence to back up the multitude of packaging now claiming biodegradability is scant at best.