What information can be found on the UN number of a container?

The correct choice reflects that the UN number provides a specific identification of the hazardous material contained within a container. UN numbers are four-digit codes assigned by the United Nations to identify hazardous substances and articles. This numbering system is vital for emergency responders to quickly ascertain the nature of the materials involved in an incident, allowing for informed and appropriate actions to be taken. Each UN number is unique to a particular substance or group of substances, thus facilitating the safe handling, transportation, and understanding of hazardous materials.

The other options do not accurately represent what is conveyed by the UN number. For instance, the weight of the hazardous material is not indicated by the UN number; this information would typically be found on the shipping documents or labels. Similarly, the specifics about shipping temperature requirements would be found in additional documentation or materials but are not encoded within the UN number. A summary of the safety data sheet (SDS) is also separate and does not correlate directly with the UN number itself, as the SDS provides detailed information about the handling and hazards of the material.