The presence of the isotope plutonium-240 in a sample limits its nuclear bomb potential, as plutonium-240 has a relatively high spontaneous fission rate (~440 fissions per second per gram—over 1,000 neutrons per second per gram),  raising the background neutron levels and thus increasing the risk of predetonation .  Plutonium is identified as either weapons-grade , fuel-grade, or reactor-grade based on the percentage of plutonium-240 that it contains. Weapons-grade plutonium contains less than 7% plutonium-240. Fuel-grade plutonium contains from 7% to less than 19%, and power reactor-grade contains 19% or more plutonium-240. Supergrade plutonium , with less than 4% of plutonium-240, is used in . Navy weapons stored in proximity to ship and submarine crews, due to its lower radioactivity.  The isotope plutonium-238 is not fissile but can undergo nuclear fission easily with fast neutrons as well as alpha decay. 
Initial dose based on previous asthma drug therapy and disease severity; 100 mcg via oral inhalation once daily is the usual recommended starting dose for patients not on an inhaled corticosteroid. After 2 weeks of therapy, if asthma symptoms are uncontrolled, increase dose to 200 mcg via oral inhalation once daily. Max: 200 mcg once daily. Administer at the same time each day. The maximum beneficial effect may not be achieved for up to 2 weeks or longer after starting treatment. Titrate to the lowest effective dose once asthma stability is achieved.
Patients’ inhaler technique can be improved by brief education, including a physical demonstration, from a health professional or other person trained in correct technique. 68 The best way to train patients to use their inhalers correctly is one-to-one training by a healthcare professional (. nurse, pharmacist, GP, specialist), that involves both verbal instruction and physical demonstration. 74 , 62 , 75 , 76 Patients do not learn to use their inhalers properly just by reading the manufacturer's leaflet. 75 An effective method is to assess the individual's technique by comparing with a checklist specific to the type of inhaler, and then, after training in correct technique, to provide written instructions about errors (. a sticker attached to the device). 60 , 73