What is identified as a source of physical contamination?

Physical contamination in food safety refers to the presence of foreign objects that can cause harm to consumers, primarily when these objects are ingested. The correct answer, which identifies hair or metal shards as a source of physical contamination, highlights the tangible nature of these contaminants.

Hair, for instance, can easily fall into food during preparation or serving and can lead to consumer complaints or even harm if ingested. Similarly, metal shards can break off from machinery or utensils and find their way into food products, posing a serious risk to those who consume them.

Understanding types of contaminants is crucial for maintaining food safety standards and ensuring that food served is free from harmful substances. The other choices relate to different types of hazards: cleaners are chemical contaminants, pesticides are also chemicals associated with agricultural processes, and viruses are biological contaminants. Each type of contamination poses its own risks and requires specific prevention strategies, but they do not fall under the category of physical contamination as defined in food safety practices.