D made a determination that occupational exposure to cotton dust presented a material health hazard to workers. Three groups immediately challenged the ruling: (1) representatives of the cotton textile industry and (2) nontextile industries who claimed that the standard was unwarranted and infeasible; and (3) their employee unions, who attacked two provisions of the standard as too lax, but supported the rest. Impairments associated with exposure to cotton dust range from acute but reversible reactions to irreversible, chronic obstructive pulmonary disease. Cotton dust exposure can produce or aggravate respiratory symptoms characteristic of chronic bronchitis, asthma, and emphysema. A specific, debilitating disease called byssinosis or brown lung disease comes from the effect of cotton dust on the respiratory passages. The exact etiology is still not completely understood nonetheless, its progressively disabling symptoms are well documented. D published an Advanced Notice of Proposed Rulemaking on cotton dust. D requested interested parties to submit their views on the National Institute of Occupational Safety and Health (NIOSH) recommendations and related issues concerning a proposed standard. D received comments from scientists, labor unions, industries, cotton growers, and governmental representatives. A proposed revision, published on December 28, 1976, called for an exposure limit of 200 g/m 3 of cotton dust. D provided 90 days for interested parties to submit written comments. D conducted hearings in three cities for a total of 14 days. The comments and exhibits received before the hearings, the written and oral testimony of the hearing participants, and post-hearing comments and briefs comprise the informal rulemaking record for the final cotton dust standard promulgated by the agency. This record exceeds 105,000 pages in length; it includes comments from 263 parties and testimony from 109 participants at the hearing. The Final Standard and its accompanying statement of reasons fill 68 pages of the Federal Register. D promulgated the cotton standard in an effort to reduce the health risks to cotton workers. Part of the standard sets 'permissible exposure limits' (PELs) for each manufacturing operation and industry that exposes workers to cotton dust: (1) 200 micrograms per cubic meter (200 g/m 3) as the PEL for lint-free respirable cotton dust in yarn manufacturing; (2) 750 g/m 3 for slashing and weaving operations in the cotton industry; and (3) 500 g/m 3 for all other processes in the cotton industry and for all non-textile industries that expose workers to cotton dust. D established a four-year implementation period during which employers are expected to achieve compliance. If an employer establishes that the required controls are infeasible, he can obtain an administrative variance from the standard, but he must make respirators available to protect his employees until he achieves compliance. The standard also requires employers to monitor employees' exposure to cotton dust, to provide medical surveillance and employee education, and to post warning signs about the health risks. Everybody in the world appealed all for different and conflicting reasons.