"Possible contamination" means that something may have been exposed to harmful substances or impurities, which could affect its purity, quality, or safety. Full definition
If it is possible contamination of the food, commercial diets are far more likely to be the source of that. (consciouscat.net)
However, a good brand of commercial dog food is best in terms of ensuring a fully balanced diet and avoiding possible contamination from raw foods. (ipupster.com)
• Businesses where food is sold have to think about possible contamination or poisoning. (inc.com)