Yes, it's perfectly safe to disable WebRTC. Many people including myself have done it, too. However, in some scenarios disabling it can actually keep you better protected - an example would be disabling it to prevent a WebRTC leak which would result in your real IP address being given away whilst browsing with a proxy/proxy extension (known as extensions for VPN).
WebRTC is widely used for things such as voice/video web applications (RTC stands for Real-Time Communication). You can re-enable it at any time should you need to use a web application which requires it to be enabled and used to function correctly.
