A waste liquid containing a body fluid released from a patient during surgery and medical treatment (hereinafter, the wording "waste liquid" means the infectious liquid containing a body fluid ) is aspirated and collected in a collecting bottle with an applied negative pressure. After that, the waste liquid is flushed down the drain. For this purpose, a glass bottle (the capacity of which is in the range of 5 to 8 liters) is used. This bottle is, however, heavy, and is cumbersome in discarding the hazardous waste liquid. Moreover, from a point of view of environmental protection, medical waste should be sterilized before being returned to environment. Under process of autoclave sterilization, the waste liquid containing the body fluid emits an offensive smell. Germicidal agent becomes ineffective in the presence of highly concentrated organic mater such as blood cells and fat. Thus, in recent years, the trend is toward in use of one use only container made of synthetic resin. The one use only container can be incinerated together with the waste liquid.
As the disposal container, U.S. Pat. No. 3,685,517 discloses such a treating container 55 as shown in FIG. 6, wherein a synthetic resin made bag member 54 is welded to a firm synthetic resin made cover 53 with an outlet 51 and an inlet 52. This container 55 is used in such a manner that the bag member 54 is inserted in a firm pressure reducing vessel 56 and the upper cover 53 is air-tightly fitted to the opening of the pressure reducing vessel 56. The upper cover 53 has a first through-hole 57 and a second through-hole 58. The first through-hole 57 communicates with the space between the inner surface of the pressure reducing vessel 56 and the outer surface of the bag member 54, whereas the second through-hole 58 communicates with a conduit 59 projectingly provided in the bag member 54. When the outlet 51 is connected to a pressure reducing source, the bag member 54 is swelled in the pressure reducing vessel and concurrently the waste liquid is aspirated through the inlet 52.
Using the one use only container eliminates the troublesome works such as a work for discarding the waste liquid and a work for washing the interior of the bottle after discarding the waste liquid. The prior art container, however, has the following disadvantage: namely, although the container itself is extremely reduced in its weight by changing the material thereof from glass to synthetic, the container filled with the waste liquid is still heavy because the content therein is mainly composed of water. This takes a lot of labor in its transport and requires a large amount of energy in its incineration.
In view of the above situation, the present invention has been made. Accordingly, an object of the present invention is to provide a method for treating a waste liquid containing a body fluid, which makes easy the transport of the container and subsequent incineration: and a container suitable for carrying out the method.