Whenever anyone utilizes technology they must now the risks involved. No form of electronic communication can be considered 100 percent safe from any and all observers. Make sure you have a plan about what you'll do if the wrong person finds out you made contact as a whistleblower.
Do not contact anyone from your work computer or phone. Your bosses can track your use of these devices. The same goes for your personal mobile phone if you've ever installed apps from your employer even if you later uninstalled them.