Section 408.17707. Entry into bins, silos, tanks, and other grain storage structures.

(1) This rule applies to employees entering bins, silos, tanks, and other grain storage structures, except for entry through unrestricted ground level openings into flat storage structures in which there is no toxicity, flammability, oxygen deficiency, or other atmospheric hazards, which is covered by R 408.17719. For the purposes of this rule, the term "grain" includes raw and processed grain and grain products in facilities specified in R 408.17701(b).

(2)   All of the following actions shall be taken before employees enter bins, silos, tanks, or other grain storage structures:

(a)   An employer shall issue a permit for entering bins, silos, tanks, or other grain storage structures unless the employer or a representative of the employer who would otherwise authorize the permit is present during the entire operation. The permit shall certify that the precautions contained in this subrule have been implemented before employees enter bins, silos, tanks, or other grain storage structures. The permit shall be kept on file until completion of the entry operations.

(b)   All mechanical, electrical, hydraulic, and pneumatic equipment that presents a danger to employees inside grain storage structures shall be de-energized, disconnected, locked out and tagged, blocked off, or prevented from operating by other equally effective means or methods.

(c)   The atmosphere within a bin, silo, tank, or other grain storage structure shall be tested for the presence of combustible gases, vapors, and toxic agents when an employer has reason to believe they may be present. Additionally, the atmosphere within a bin, silo, tank, or other grain storage structure shall be tested for oxygen content, unless there is continuous natural air movement or continuous forced-air ventilation before and during the period employees are inside the bin, silo, tank, or other grain storage structure. If the oxygen level is less than 19.5%, if combustible gas or vapor is detected in excess of 10% of the lower flammable limit, or if toxic agents are present in excess of the ceiling values listed in Occupational Health Standard Part 301 Air Contaminants for General Industry, as referenced in R 408.17701c, or if toxic agents are present in concentrations that will cause health effects that prevent employees from effecting self-rescue or communication to obtain assistance, then both of the following provisions apply:

(i)     Ventilation shall be provided until the unsafe condition or conditions are eliminated. Ventilation shall be continued as long as there is a possibility of recurrence of the unsafe condition while the bin, silo, tank, or other grain storage structure is occupied by an employee.

(ii)    If toxicity or oxygen deficiency cannot be eliminated by ventilation, then an employee entering the bin, silo, tank, or other grain storage structure shall wear an appropriate respirator. Respirator use shall be in accordance with the requirements of Occupational Health Standard  Part  451   Respiratory  Protection,   as  referenced  in R 408.17701c.

(3)   If an employee enters a grain storage structure from a level at or above the level of the stored grain or grain products, or if an employee walks or stands on or in stored grain that is deep enough to pose an engulfment hazard, then employer shall provide the

employee with a body harness that has a lifeline or a boatswain's chair that meets the requirements of  General  Industry  Standard   Part  5  Scaffolding,   as  referenced  in R 408.17701c. Both of the following provisions apply:

(a)     The lifeline shall be so positioned and of sufficient length to prevent the employee from sinking more than waist deep in the grain. If the employer can demonstrate that the protection required by this rule creates a greater hazard, then the employer shall provide an alternative means of protection that has been demonstrated to prevent an employee from sinking more than waist deep in the grain.

(b)    If an employee is standing or walking on a surface that the employer has demonstrated does not pose an engulfment hazard, then the lifeline or alternative means may be disconnected or removed.

(4)   An observer who is equipped to provide assistance shall be stationed outside the bin, silo, tank, or other grain storage structure being entered by an employee. Visual, voice, or signal line communications shall be maintained between the observer and the employee entering the bin, silo, tank, or other grain storage structure.

(5)   An employer shall provide equipment for rescue operations that is specifically suited for the bin, silo, tank, or other grain storage structure being entered.

(6)     An employee acting as an observer shall be trained in rescue procedures, including notification methods for obtaining additional assistance.

(7)    An employee shall not enter a bin, silo, tank, or other grain storage structure underneath a bridging condition or where a buildup of grain products on the sides could fall and bury the employee.

(8)   An employee shall not walk down grain or perform a similar practice where an employee walks on grain to make it flow within or out from a grain storage structure. An employee shall not be on moving grain.

History: 1988 AACS; 1997 AACS; 2014 AACS.