A container (10) for irradiation comprises a flexible, flat collapsible wall (12, 13) defining a sealed chamber (36), the plastic material of the wall (12, 13) is substantially transparent to irradiation, typically ultraviolet radiation. Access ports (22, 24, 26) are provided for communicating through the wall (12, 13) to the chamber (36). A flap (32) is provided, integral with the wall (12, 13) and spaced from the chamber (36), and carries identifying indicia (38) including a typical bar code indicia (40), so that the wall (12, 13) may be at least substantially free of opaque indicia. Also, structure may be provided for detecting and indicating exposure of the container to irradiation, such as ultraviolet sensitive tape (50) adhering to the flap (32). Alignment holes (46) may be provided, typically in the flap (32), to facilitate orientation of the container (10) with apparatus for irradiation (51) and apparatus for bar code reading (72), making use of alignment pins (70) carried by such apparatus (51).