“…In other works, on the expression for the calculation of the erythematous dose, the exponent mentioned above seems to take the value of unity, thus using a linear relationship to calculate the dose, and from this it is possible to establish the exposure time necessary to produce erythema on the skin. Currently, an expression used for the calculation of the sun exposure time necessary to induce erythema would be equation (2) [ 22 , [47] , [48] , [49] , [50] ]: …”