You don't say what camera you are using it on. In any case your sensor won't be hurt by bright reflected light, say from a white building lit by bright sunlight. But it may be over exposed. This depends on the efficiency of the grating and the amount of dispersion it gives. I'd expect light levels are likely low enough not to be a problem. Not having ever used one I can't say for sure and the camera used will have some say in this as well. They very greatly in shutter speed depending on model. If it is you'll need neutral density filter to get the light down to a level that doesn't overwhelm the chip. You'll also need to know how "neutral" your filter is or it will skew the spectrum you are trying to measure.