1. Chicken racks themselves do not contain toxic substances, but if they are not properly handled during the grilling process, there may be hygiene problems, such as contamination by bacteria or viruses. There may also be food safety problems, such as bacterial or mold growth, if unfresh chicken racks are used.

2. Duck intestines may contain bacteria and parasites, which may cause food poisoning or gastrointestinal upset if not properly handled and cooked.