ethylene 30 oxide in the air may have harmful effects on one breathing the air for about 8 hours. Propylene oxide is less toxic than ethylene oxide but is still highly toxic. A concentration of 100 parts per million of propylene oxide breathed for about 8 hours may have undesirable 35 effects. Naturally, when fuel air explosive devices are stored in a confined area such as aboard a ship, exposure for 8 hours is not unusual.

Another drawback common to ethylene oxide and propylene oxide is the fact that both have relatively low 40 boiling points, 10.4° C. and 34.2° C. respectively. This makes the two difficult to handle in loading operations. High vapor pressures also contribute to difficulty in handling.

A drawback particularly associated with ethylene 45 oxide is its tendency to polymerize during storage. Left alone in a fuel air explosive weapon or other container, ethylene oxide tends to self polymerize. The polymerized material is unsuitable for use as a fuel for a fuel air explosive device. Unpolymerized ethylene oxide, on the 50 other hand is highly desirable as a fuel insofar as detonability is concerned. Clouds containing from as little as 3 up to as much as 100 percent by volume of ethylene oxide are detonable. The detonation limits of propylene oxide, on the other hand, range from about 3.1 to about 55 27.5 percent by volume.

SUMMARY OF THE INVENTION

It has now been found that 1,2-butylene oxide, when used as a fuel for fuel air explosive devices, exhibits marked superiority over either ethylene oxide or propylene 60 oxide. The marked superiority stems from the fact that 1,2-butylene oxide is about 3 times safer than propylene oxide when long exposure to it is required and about 3.5 times safer than ethylene oxide. Insofar as ease of detonation is concerned, 1,2-butylene oxide has about 65 the same explosive limits as propylene oxide. However, 1,2-butylene oxide is significantly easier to handle because its boiling point is nearly twice that of propylene oxide—63° C. as opposed to 34.2° C.—and over 6 times that of ethylene oxide. According to this invention 1,2-butylene oxide may be used in either its natural 5 liquid state or gelled with a hereinafter named gelling agent.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

10 In one embodiment of this invention, neat 1,2-butylene oxide liquid is used as the fuel in a fuel air explosive weapon in lieu of the previously most commonly used fuels, ethylene oxide and propylene oxide. It has been found that butylene oxide is significantly less toxic than 15 either of the two commonly used oxides. Air containing 400 parts per million of 1,2-butylene oxide may be breathed safely for up to 8 hours with no undesirable results as compared to 100 parts per million for propylene oxide and only 50 parts per million for ethylene 20 oxide.

1,2-butylene oxide offers a second distinct advantage over ethylene oxide and propylene oxide. Its boiling point is 63° C. as opposed to 10.4° C. and 34.2° C. respectively 25 for the other two oxides. Thus, loading operations are much easier to carry out. No special equipment is needed for its handling.

Tests have shown that, insofar as ease of detonation is concerned, 1,2-butylene oxide is similar to propylene 30 oxide. Its explosive limits range from about 3.1 to 25.1 percent by volume as opposed to 3.1 to 27.5 percent by volume for propylene oxide. Thus, its significantly lower toxicity can be taken advantage of with very little loss in explosive efficiency. 35

Another factor contributing to the ease of handling of 1,2-butylene oxide is its vapor pressure. The vapor pressure