What is the appropriate action when a reagent bottle is found to be unlabelled?

When a reagent bottle is found to be unlabeled, the most appropriate action is to dispose of it. This is crucial for safety and compliance because using an unlabelled reagent poses significant risks. Without clear identification, there is no way to know the chemical's composition, concentration, or proper handling instructions, which could lead to hazardous reactions, health risks, or contamination of experiments.

Disposing of the unlabelled reagent ensures that there is no chance of accidental use or misidentification, which is a fundamental principle of laboratory safety. Reagents must always be stored and labeled correctly to prevent any dangerous situations that could arise from unknown chemical properties or interactions.

Other options are less suitable for safety and protocol adherence. Using an unknown reagent could lead to serious accidents or compromised results. Labeling it with a marker is not responsible since it adds ambiguity rather than clarity. Asking a colleague might seem helpful, but it still doesn’t guarantee that the reagent’s nature can be confirmed or trusted.