My DIY safelight consisting of six 635nm red LEDs reinforced with a single layer of Rubylith to suppress tiny slivers of non-red emission spikes, is hideously safe, as well as quite bright. Pre-flashed to just below threshold, Ilford MGIV FB & RC tested absolutely safe—to both the eye and a reflection densitometer—out to a 60 full minutes, at which time the test was voluntarily terminated as being pointless beyond that.
And the LEDs were far, far less expensive than a traditional safelight. And are rated for 50,000 or so hours of continuous use. That's 10,000 5-hour darkroom sessions.