What does a negative patch test result allow a practitioner to do?

A negative patch test result indicates that there was no allergic reaction in the client to the substances tested. This typically means that it is safe for the practitioner to proceed with the service, as the materials used in the treatment are not likely to cause a negative reaction. The purpose of the patch test is to identify potential allergic responses before applying products that may contain irritating or reactive substances. Since the test did not reveal any issues, it provides the necessary reassurance to move forward without the risk of adverse reactions related to the substances in question.

The other options would not be appropriate actions in this scenario, as stopping the service or observing the client for further reactions would suggest uncertainty regarding the safety of the products used, which is not warranted after a negative result. Offering alternative treatments isn’t necessary unless there were concerns or indications from the patch test that would suggest such an action is needed.