The board may authorize the destruction of any record, paper or document, by a four-fifths vote, if the documents have been inadvertently exposed to asbestos fiber in a quantity which presents a risk to the health and safety of persons who handle the record, paper or document, and if the board determines that the risk to these persons is greater than the benefit to be derived from the retention of the record or, alternatively, that the cost of sterilizing the records far exceeds their value. The decision of the board shall be final.