All I know is that a little is all it takes. This is a fair sized 4 oz bottle and I have been using it in my kitchen for a few weeks, and I still have more than half of it left.
I have been putting some in my dish washing water, and have a spray bottle with lemon oil and some vinegar for spraying the counters. Both have natural sanitizing properties so it is really good to use in the kitchen.
You can use the lemon oil in homemade soaps too. Or in diffusers. It smells wonderful. A drop in the laundry can make your clothes smell good too.
A couple of drops in a corner can make the whole room smell nice for quite a while.
Lemon Oil is supposed to be good for other things, like cleaning your skin, and even removing stains. Rinsing your hair with it can help with scalp issues, and make your hair smell nice.
This graphic from Organic Facts lists a few different uses. I haven’t tried it for anything but cleaning, sanitizing, and making things smell good. I suppose just having it in the air can help if you have asthma.
In any case I like this Lemon Oil.