OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

February 26, 1999



SUBJECT: OSHA Enforcement: Vertical Food Mixers


This memorandum sets out OSHA's enforcement policy for safeguarding vertical food mixers. These mixers are used frequently in bakeries, restaurants, pizza shops, and nursing homes.

OSHA's bakery standard, 29 CFR §1910.263, does not address point-of-operation and rotating-part hazards created by vertical food mixers. However, these hazards as related to vertical food mixers are covered by OSHA's general standards for machine guarding at §§1910.212(a)(1) and .212(a)(3)(ii). Normally, when the rotating parts above the point of operation are guarded as required by §1910.212(a)(1), hazards at the point of operation are also protected.

Employee Exposure

As part of OSHA's burden of proof before the Occupational Safety and Health Review Commission (Review Commission), OSHA must show that an employee is exposed to the hazard being cited. Thus, the Field Inspection Reference Manual (FIRM) in Chapter II, on page II-14, at paragraph A.4.b., requires the compliance officer to record all facts pertinent to an apparent violation. It states, in part:



... [Compliance officers] shall record at a minimum the identity of the exposed employee, the hazard to which the employee was exposed, the employee's proximity to the hazard, the employer's knowledge of the condition, and the manner in which important measures were obtained.... [emphasis added]

The NOTE after this paragraph states:

If employee exposure (either to safety or health hazards) is not observed, the [compliance officer] shall document facts on which the determination is made that an employee has been or could be exposed.

The issue of employee exposure is also addressed by the FIRM, in Chapter III, Inspection Documentation under the discussion of Violations. On page III-5, paragraph C.1.b.(2) states: "The proximity of the workers to the point of danger of the operation shall be documented."

Although the Review Commission's test for establishing exposure in machine guarding cases is, we believe, too stringent, it is the test which we currently must meet. The test was most recently restated by the Commission in Fabricated Metal Products Inc., 18 BNA OSHC 1072, 1074 (No. 93-1853, 1997) as follows:

... in order for the Secretary to establish employee exposure to a hazard she must show that it is reasonably predictable either by operational necessity or otherwise (including inadvertence), that employees have been, are, or will be in the zone of danger. We emphasize that, as we stated in Rockwell, the inquiry is not simply into whether exposure is theoretically possible. Rather, the question is whether employee entry into the danger zone is reasonably predictable.

The Commission will usually not find there to be a reasonable predictability of inadvertent contact unless the employee's hands are in the "immediate vicinity" of the hazardous area.

Two judge's decisions show how this test has been applied in the context of vertical mixers. In Station 104, Inc., OSHRC Docket No. 88-336, 1990 CCH OSHD ¶28, 920, the Administrative Law Judge (ALJ) held the mixing bowl of the vertical mixer guarded the dough hook's point of operation, and the exposed part of the agitator remained well within the protective circumference of the bowl. In Top Taste Bakeries, Inc.; Home Bakery and Coffee Shop, OSHRC Docket Nos. 89-0977 and 89-2398, 1990 CCH OSHD ¶28,962, the ALJ held there was a lack of proof of significant risk of injury given the vertical mixer's location and method of operation and the low incidence of actual injuries.

Therefore, based on these ALJ decisions and FIRM procedures, the compliance officer must carefully determine if there is employee exposure. The following are some factors that must be taken into consideration when evaluating exposure to a vertical mixer's hazards such as point-of-operation, ingoing nip points, and rotating parts:

  • How the mixer functions (e.g., visibility of agitator, ability to accidently switch on);
  • How worker performs operations (e.g., adding ingredients, scraping the bowl, checking dough for consistency);
  • Distance worker is from point-of-operation hazard or rotating part -- how close does worker get to hazard during operation;
  • Tools, clothing, jewelry, or hair of worker that might get caught or fall into mixer;
  • Type of guarding in place or provided, if any;
  • Any slipping or tripping hazards in the area.

Citation Policy

When there is employee exposure to any of the normal production hazards mentioned in §1910.212(a)(1), then one or more methods of machine guarding shall be provided, as appropriate, to protect the exposed workers.

For example, when there is employee exposure to a normal production point-of-operation hazard, the compliance officer shall cite §1910.212(a)(3)(ii) and document employee exposure when the point of operation of a vertical mixer is not properly guarded, or if guarding is not feasible and there is no effective safeguarding work practice in place.

Safeguarding a worker from potential exposure to the machinery hazard(s) of a mixer must be provided by a barrier guard or a safeguarding device. When safeguarding by barrier guard or a device is not feasible, safeguarding by maintaining a safe distance may be used. An employer who adopts a work practice of "safe distance" protection must be prepared to demonstrate an effective work practice to OSHA. An employer can meet this obligation by establishing and having employees follow a work practice which includes exposure prevention procedures, training, and enforcement of these procedures. Exposure prevention procedures may include the manner in which the mixer is operated that keeps the worker at a safe distance from the point-of-operation/rotating part hazard. Work practices, however, are not to be used in lieu of necessary machine guarding when guarding is feasible. Replacement of old mixers with new units, which have the required safeguarding, is an option employers have when the old mixers cannot be upgraded or retrofitted with the safeguarding.

Compliance officers shall keep in mind that there may be hazards with vertical mixers during servicing and maintenance operations, in which hazardous energy could cause injury to employees. The control of hazardous energy standard (lockout/tagout), §1910.147, covers servicing and maintenance which takes place during normal production operations, if and only if either of the circumstances set forth in §1910.147(a)(2)(ii)(A) & (B) of this standard pertains. Additionally, this standard also applies when there is a potential for unexpected activation or start up, the machine can be deenergized to perform the servicing or maintenance, and there is employee hazardous energy exposure. The vertical mixers, in the event that §1910.147 applies, must be deenergized and be locked or tagged out in accordance with the procedures required by this standard.

In the event the vertical mixer's power source is a flexible cord, then the lockout or tagout of the machine is not required if the provisions of §1910.147(a)(2)(iii)(A) are met for cord and plug connected equipment. The exemption is predicated on the assumption that the use of the flexible cord is approved and suitable for the conditions of use and location as detailed in §1910.305(g).

This memorandum supersedes any regional directives or interpretations that are not consistent with the content herein. Please contact the [Office of General Industry Enforcement at (202) 693-1850], if you have any questions.