In this article, industry manufacturers answer common questions asked by building service contractors.

How many soap dispensers do I need in a restroom? What is an appropriate sink to dispenser ratio? 
The appropriate sink-to-dispenser ratio can vary by location and traffic; but we have found the ideal ratio to be one to one.
Katharina Versluis, Marketing Manager, Gent-l-kleen Products Inc., York, Pa.

This really depends on the amount of traffic and use. Best case scenario is one dispenser to each restroom sink. However, in low-traffic scenarios that have just a few sinks, one dispenser may be enough to serve two sinks. It really is weighted on where the restroom is, how many people use the restroom on a typical day and what kind of building it is in (school, office, plant, healthcare, etc). 

Placement of a soap dispenser should be such that a user does not need to walk away from the sink to dispense the soap. This could present a hazard if soap falls out of the hand onto the floor as they are stepping back to the sink with a handful of soap. Hand soap on the floor is difficult to clean up, is slippery and presents a slip and fall hazard. 
Lori Huffman, Head of Marketing, North America, STOKO An Evonik Brand, Greensboro, N.C.

Generally you should have a soap dispenser next to each sink to reduce or eliminate soap or water spills. Mounting one dispenser between two adjacent sinks is acceptable, but one dispenser per sink or user is the best ratio.

You may also want to equip your restroom with a common hand sanitizer dispenser for kids or disabled people that can’t reach the soap or faucets.
Dan Renner, Director of Marketing, Kutol Products Co., Sharonville, Ohio 

Do you have a recommendation for how many hand sanitizer dispensers are needed in a facility based on occupancy? Or is locale more important? 
Locale is more important. When placed at entrances to public and social areas as well as hand washing stations, hand sanitizer use increases and, in turn, becomes more effective overall.
Katharina Versluis, Marketing Manager, Gent-l-kleen Products Inc., York, Pa.

Location, location, location, and it depends on the type of facility. Every entryway should have sanitizer no matter what type facility, either on a stand or wall close to the door. Common sense rules that heavily traveled areas of the building or main entryways could have two dispensers installed, while secondary areas, just one. 

In schools, the best case is to have a dispenser in each classroom. If that is not possible, a dispenser in the hall between two classrooms would still be beneficial as would one outside each restroom. (Hand washing with soap and water should be encouraged inside each restroom). 

In non acute healthcare facilities, sanitizer should be placed at entryways and in or just outside each patient or examination room. 

In general, the rule of thumb is, depending on the traffic, sanitizer should be placed in prominent, easy to access places so as to encourage use as much as possible
Lori Huffman, Head of Marketing, North America, STOKO An Evonik Brand, Greensboro, N.C.

The amount of users or occupancy is not as important as locale. You want to make hand sanitizing convenient and visible and place them where people will most likely use them. The most popular locations are in common areas like the lobby, waiting room, cafeteria, classroom and hallway. In hospitals, inside and outside the patient room is extremely important. 
Dan Renner, Director of Marketing, Kutol Products Co., Sharonville, Ohio