Another poster has hit on the right option GDPR.
Dear Manager, HR and Data Protection Officer
I, along with my colleagues, have been asked to download WhatsApp and to join a WhatsApp group that has been set up for Business Continuity purposes.
I am concern at this request for a number of reasons. The General Data Protection Regulations (GDPR) and (employer) Privacy Policy both set out the lawful way in which my personal data can be held and processed.
From my limited knowledge of WhatsApp I understand that everyone in a group can see my personal data and process it by contacting me directly or by sharing it with anyone. I do not believe this complies with the GDPR or the Privacy Policy.
In addition, WhatsApp, like many apps, may capture and process my personal data. Again I do not believe this complies with GDPR or the Privacy Policy.
I have provided my personal phone number and email so I can be contacted in an emergency, including Business Continuity. I believe this is sufficient and complies with GDPR and the Privacy Policy.
I would appreciate you reviewing the request to download and join a group against the requirements of the GDPR and the Privacy Policy.
Thank you