A nurse checks supplies before performing a sterile dressing change. The facility treats the outer 1 inch of a sterile field as contaminated. A conversion reference is 1 inch = 2.54 cm. Click the item that must be replaced because part of it lies within that border.

A. A extends into the outer border: its left end is only 1 cm from the drape edge.

Assess the entire instrument rather than its centre or its label. One portion of A contacts the outer 2.54-cm border, so it cannot be treated as sterile. The other supplies are farther from every outer edge.

The observations are fictional teaching data. Apply the stated context; the selected feature does not by itself replace a complete bedside assessment.

Any part of an item contacting a contaminated boundary affects the whole item.

Any part of an item contacting a contaminated boundary affects the whole item.

B lies centrally with adequate separation from each edge. C is 4.5 cm from the top edge and farther from the others. D remains 5.5 cm from the right edge and 6 cm from the bottom edge. The tray underneath is not the boundary used for the field.

• Sterile-field boundary and whole-object contamination — Any part of an item contacting a contaminated boundary affects the whole item.
• Comparison with context — C appears close to the top edge but is beyond the contaminated border.