How to make sprayable air freshener:

1). Combine Fragrance Oil or Essential Oil with Polysorbate 20 in a 1:1 ratio and mix well.
2). Add about 10% Isopropyl Alcohol (if you have 100ml fragrance oil / PS20 mix, add 10ml)
3). Add a few drops of liquid colour if required
4). OPTIONAL: Use a preservative such as Kathon CG for longer shelf-life
5). OPTIONAL: Add Dipropylene Glycol for enhanced diffusion ability
6). Add de-ionised water so that your concentrate is 5 to 10% of the total volume (If your concentrate is a total of 100ml, add 900ml water).

Things to Note

Fragrances generally will make the liquid opaque (milky). If you desire a clear liquid, you will need to find a fragrance that remains translucent in water emulsion.
It is wise to check the IFRA certificate for the fragrance oil you wish to use. Although the vast majority of fragrance oils are rated as 20% or above safe usage for air freshener, there may be some that you will need to use a lower amount for. Typically, you wouldn’t use more than 5-10% fragrance oil in any air freshener.
Fragrance Oil as it is will not mix with water. An emulsifier such as Polysorbate 20 is needed to allow the oil to form an emulsion with water. This gives an even spread of fragrance oil within the water without any settlement issues.
Bitrex can be added to air fresheners for increased safety with regards to accidental ingestion, but the problem is it becomes possible to taste the bitter substance when the air freshener is sprayed into the air, so this is not feasible.
For a sprayable disinfectant, add BAC 50 0.07g per 100ml. This will render the product unsuitable for use as a room spray as BAC 50 is not to be breathed in.

F-JAS Carries a range of Air Freshener Making Supplies HERE.