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.

March 12, 1985

Ms. Inge Lundstrom
National Board of Occupational Safety
and Health
Chemistry Section 3
S-171 54
Ekelundsvagen 16
Solna, Sweden

Dear Ms. Lundstrom:

This is in response to your letter of February 18, addressed to the Assistant Secretary for Occupational Safety and Health.

You asked in your letter for information about dust explosions in powdered milk production. The Occupational Safety and Health Administration (OSHA) does not have any specific standards that could be applied to the powdered milk industry, however, many of OSHA's General Industry (GI) Standards (copy enclosed) might be used to control dangerous situations in that industry. For example, it is believed that many explosions in industries like the powdered milk industry are caused by large accumulations of dust. This situation is covered, in a general fashion, by OSHA's housekeeping standards (in the GI standards at 1910.22(a)(1)). It is also thought that careful attention to electrical ignition sources may reduce the number of explosions that occur in industries which tend to generate dusty conditions: OSHA's standards for electrical applications in the workplace (Subpart S of the GI standards which begins at 1910.301) may be helpful in eliminating or lowering the possibility of explosions triggered by improper wiring or grounding. OSHA conducts regular inspections in all industrial sectors to assure that its standards are being followed. Failure of companies to adhere to the OSHA standards is subject to enforcement action which may include issuance of citations and/or penalties.

I am also enclosing, for your information, documentation about an explosion at a powdered milk production plant that took place in 1980, details of which may be of interest to you. If I may be of further assistance, please feel free to write again.


Anthony E. Goldin
Director of Policy


Office of the Special
February 4, 1980

C. H. Jones, Manager, Land O'Lakes Company, 614 McKinnley Place, Minneapolis, Minnesota, said:

Their corporate offices are located at 614 McKinnley Place, Minneapolis, MN. They have a mill where they manufacture milk replacer for calves, pigs, and lambs located across the street. The address of the mill is: 2300 Kennedy, NE, Minneapolis, MN. The mill consists of a warehouse where the product is bagged and stored, and an elevator with 18 steel bins, and a number of legs.

On February 1, 1980, at 10:55 p.m., they experienced an explosion and fire. There was one person dead, and eight persons injured. Of the eight injured, one is critical, four are serious, two are satisfactory, and one was released after treatment. They were making calf replacer at the time of the explosion. The initial explosion was in ingredient bin No. 6 in the mixing area. They were ready to fill bin No. 6 with whey powder. The unloader was on top of bin No. 6, and he lowered a drop cord into the bin to see that the bin was empty (a common practice). A conveyor (auger) was running at the bottom of the bin. The drop cord got into the conveyor, the cord was cut, causing the explosion. The drop cord was found wrapped around the conveyor following the explosion. The explosion spread throughout the steel bins and the warehouse, and the mill was considered nearly a total loss.

Jim Carlson, Chief Arson Investigator, Minneapolis Fire Department, Minneapolis, Minnesota, said:

His records showed they received the first alarm at 2259 hours on February 1, 1980, from Land-O-Lakes, followed by three additional alarms with the fourth alarm being called in at 2318 hours. Nine persons were injured, and one died later. The loss to the building was estimated at $1,500,000.

Their investigation showed there was an explosion in the mill followed by fire throughout the facility. The explosion first occurred in bin No. 6, and was caused by a drop cord which became entangled in an auger at the bottom of bin No. 6 and shorted out. Investigation is continuing.