The phrase "alerting them about" is correct and usable in written English.
It can be used when you want to inform someone about a specific issue or situation that requires their attention.
Example: "I will be alerting them about the changes in the schedule as soon as I receive confirmation."
Alternatives: "notifying them of" or "informing them about".
Letters will be sent to all potentially affected individuals alerting them about the security breach, the department said.
Then, Mr. Bennight said, he left a voice mail message at his local F.B.I. office alerting them about the comment.
In late 2010, St . Judesent a letter to doctors alerting them about data showing that the silicone coating of the Riata lead could wear away.
Additionally, United will now automatically send daily reports to airport managers around the country, alerting them about what animals to expect to arrive and depart from their airport.
For example, they can be invaluable for seniors by not only providing them with information and answers to their questions, but also by reminding them to take their medicine or alerting them about upcoming doctors' appointments.
It's tough to ignore a popup notification that your friend just watched a video called "Cat rides skateboard" – you're going to want to see for yourself, and then your friends will see an update alerting them about the video, creating an endless loop.
The police said that several people tried to alert them about the driver of the pickup truck, identified as Michael R. Gagnon, 24, of Adrian, Mich.
The North Face plans to eventually send branded texts when people arrive at a hiking trail or mountain to alert them about weather conditions or logistics for a ski competition, for example.
They had, for example, called the police to alert them about their protest as it began, they were peaceful, and no one was hurt, merely inconvenienced, during the protest.
(See my suggestions on how to do better by using a password manager). They also failed to turn on an additional protection from Nest called two-factor authentication, which would have alerted them about unauthorized access with a text message.
