Generally speaking, the splitting-up of wages/salary payable to employees into basic and other allowances is a subject-matter of collective bargaining on wage determination and wage revision. Even in such negotiations the types of various allowances and their relative proportions to gross wages are determined by various factors such as the extent of the indirect financial commitments incurred by the employer towards social security obligations and other fringe benefits, periodical direct financial implications on a/c of the raise in the cost of living, additional and special expenses to be incurred by the employees by the nature of their duties, place of employment etc. Washing allowance is one such allowance payable to the employees on a/c of the compulsion to wear uniform. To my knowledge, there are no statutory prescriptions.