The product label for Pyrocide 300 indicates to apply at the rate of 1 fluid ounce of concentrate per 1,000 cubic feet of space, filling the room with mist. Vacate treated area and ventilate before re-entry. When mixing add the concentrate first, then dilute with oil, then agitate. If there is a good agitation in the mixing tank or unit, then the mixing order is not as important.
1 part concentrate in 2 parts oil is just the number of ounces of concentrate times 2, this would be the amount of oil to mix. Ex. 1 oz Pyrocide + 2 oz oil, 2 oz Pyrocide + 4 oz oil, 3 oz Pyrocide + 6 oz oil, etc.
You can view the product label here
It is safe for occupants to reenter an area that was treated with Pyrocide 300 after the treated area has dried and odor has dissipated. This normally takes a couple of hours.