Table 1. Classification of dermal responses (Draize Scale NOM-039-SSA1-1993).

Formation of erythema and flaking	Grade
No erythema	0
Slight erythema (barely perceivable)	1
Defined erythema	2
Moderate to severe erythema	3
Grave erythema (redness) and formation of pressure sores (minor and deep lesions)	4

Formation of edema	Grade
No edema	0
Slight edema (barely perceivable)	1
Minor edema (presence of borders with defined concrete elevations)	2
Moderate edema (affecting an area of 1 mm)	3
Severe edema (affecting an area greater than 1 mm)	4