information on many stages of the photolab are best found by asking the internet. You may not have a full library, nor have ready access to someone from last century. All the major manufacturers wrote guides, pamphlets, even books to provide you full reliable, useable information about their products. There were also the standard 3rd party references: British Journal of Photography, Photo-Lab Index.
As an example of google search phrase: “kodak darkroom safelight” — along with simple modification to make: “ilford darkroom safelight.”
This took less than three minutes to find and download. Much less time than going to an internet chat-forum to ask what the safelight for MYPRDODUCT would be.