One of the more in depth positions in the scientific field of operations in the US Military is the Army Chemical weapons specialist. A chemical US Army rapid response unit also is involved in issues involving combat weapons and with smoke and flame weapons, chemical or other technology management items. You can receive a lot of training in the Chemical enlisted field without being a commissioned officer.
In rare situations a Senior Enlisted Chemical Specialist may function as a temporary Chemical Officer, but as a rule such a position is a commissioned officer position. This means you need at some point to attend OCS or otherwise obtain a military commission. If you decide that you want to pursue a Chemical Officer Commission in the US Army then you will have to attend advanced training. Some of the training will be in the classroom and will be very heavy on chemistry and science coursework, while other training will be held in the field and on the job. After commissioning as a 2nd Lieutenant officer in the Army, a Chemical Army Officer candidate will attend the Chemical Basic Skills Officer Course, where you will learn tactics, leadership skills, procedures and practices, as well as operational aspects of serving as a Army Chemical Officer. You can start as an enlisted Chemical specialist and work in all elements dealing with chemical Nuclear, biological, or chemical agents and preventing contamination or damage to equipment or personnel. You can network and deal with different chemical operations with units and armed forces. It is possible to start out training as a Enlisted Chemical Specialist and work toward an eventual commission. To be a Chemical Officer in the US Army you have to be a commissioned officer, normally a 1st or 2nd Lieutenant, and you will be responsible for supervision of a Chemical Army response unit.
As an enlisted Chemical Specialist you will work to deal with different biological, chemical and nuclear type of hazards, and work to provide rapid response to different units in the Army that needs assistance in these issues. The United States Army maintains its Chemical Officers to deal with issues of Chemical, Nuclear, Biological or other weapons, and in the area of weapons of Mass Destruction.