Each excavation job as in any other case, must be evaluated as to the facts relating to the needs of a competent person, and qualified person. The professional judgement of OSHA must come into play by using our construction regulations where they apply.
Definition: A diploid cell is a cell that contains two sets of chromosomes. One set of chromosomes is donated from each parent. Examples: The diploid number of a cell is the number of chromosomes in the cell. This number is commonly abbreviated as 2n, where n stands for the number of chromosomes. For humans this equation would be 2n=46. Humans have 2 sets of 23 chromosomes for a total of 46 chromosomes:
Just to add clarification you said; there are 23 pairs of chromosomes in most diploid cells in humans. However, diploid cells by definition contain 23 pairs of homologous chromosomes (2n), therefore diploid cells always containt 23 pairs of homologous chromosomes.