If you accidentally forgot to remove an oxygen absorber from your backpacking meal, there is no need to panic. Oxygen absorbers are typically made of materials such as iron powder, activated carbon, or sodium chloride, which are non-toxic and pose no immediate health risks if accidentally ingested. However, it is generally recommended that you do not consume the oxygen absorber, as it may affect the taste and texture of your food. In addition, consuming large amounts of these materials may cause gastrointestinal discomfort or blockages. If you are concerned about the presence of the oxygen absorber in your meal, you can try removing it before consuming the food. If the absorber has already been in contact with the food for an extended period of time, it may have affected the quality and safety of the food. In this case, it is better to err on the side of caution and discard the food. In the future, it's important to always double-check your backpacking meals to ensure that all packaging materials, including oxygen absorbers, have been removed before consuming the food.