Mo. Rev. Stat. § 643.675: Cotton gins, exempt from air dispersion modeling, when.

1. For purposes of this section, the following terms mean:

(1) "Air dispersion modeling" , the process of simulating particle matter dispersion from an emission point to help predict downwind concentrations to ensure compliance with air quality standards, considering factors like wind, terrain, and building effects, in order to assess health impacts and manage pollution;

(2) "Cotton gin" , a machine that separates cotton fibers from cotton seeds;

(3) "Department" , the Missouri department of natural resources.

2. Notwithstanding any law, rule, order, decision, permit, agreement, or other relevant authority to the contrary, an owner or operator of a cotton gin that is not a class A source, as defined in section 643.020, shall not be required to submit air dispersion modeling to the department in order to obtain a construction permit for the cotton gin.