4x5 film is a large format film and is exposed using a large format camera and a 4x5 film holder. This film has a unique feature in one side of the film that lets you know which side is the emulsion side, this feature is called: a notch code. When the notch code is in the bottom left, the emulsion is facing towards you. This kind of film is harder to develop and keep the negative pristine because of its large surface area and the fact that emulsion is naturally fragile. While handling, developing and storing this film, you must never touch the emulsion and store in film negative sleeves. This will prevent scratches from occuring which can happen more often and are more likely than developing 35mm or 120mm film.
The photographic chemicals used in the lab should not cause any problems if they are handled carefully. If you experience any sensitivity to the chemicals take extra precautions to reduce exposure. If you are pregnant, or become pregnant while you plan to work with photographic chemistry, stop and seek a professional opinion for your safety.