Erythema and edema scores were used to determine the primary irritation index

ObservationValues
Erythema
No erythema0
Very slight erythema (barely perceptible)1
Well-defined erythema2
Moderate to severe erythema3
Severe erythema (beef redness)4
Oedema
No oedema0
Very slight oedema (barely perceptible)1
Slight oedema (edges of area well-defined by definite raising)2
Moderate oedema (raised approximately 1 mm)3
Severe oedema (extending beyond the area of exposure)4