Identifying and Segregating

Identifying and Segregating Contaminated Materials Reduces Hazardous Waste

Process Background

Fisher-Rosemount designs, manufactures, distributes and services high performance measurement, control, analytical and valve instrumentation worldwide. The Eden Prairie Fisher-Rosemount facility manufactures measurement instrumentation for flow, level, pressure and temperature.

During the cleaning and assembly processes, a variety of materials come in contact with hazardous chemicals, such as methanol, acetone and isopropyl alcohol. These materials include rags, gloves, wipes, swabs, mixing sticks and epoxy applicators.

All contaminated materials, whether or not they had contact with hazardous chemicals, were disposed of as hazardous waste. Fisher-Rosemount placed these materials in containers labeled, “Type A,” and managed and disposed of them as hazardous waste.

The environmental administrator at Fisher-Rosemount believed that many of the contaminated items discarded in designated “Type A” hazardous waste containers were not hazardous. The purpose of the intern project was to identify the types of waste and develop a procedure that would segregate hazardous from nonhazardous waste in order to reduce the amount of contaminated materials treated as hazardous waste.

Incentives For Change

By reducing the amount of “Type A” hazardous waste, Fisher-Rosemount could reduce its hazardous waste disposal costs, and perhaps allow the company to be reclassified from a large quantity generator to a small quantity generator.

Intern Activities

The intern’s activities focused on developing a procedure for reducing hazardous waste throughout the Fisher-Rosemount production processes. This involved:

  • dentifying and evaluating processes that generated contaminated materials;
  • identifying chemical components of process waste streams;
  • reviewing hazardous waste regulations to determine what contaminated materials were considered hazardous; and
  • developing a procedure for segregating hazardous from nonhazardous wastes.

Identifying Waste Streams and Chemical Components

The intern began the project by reviewing waste streams from all production processes throughout the facility and identifying the processes that generated “Type A” hazardous wastes. These wastes were collected from “Type A” waste containers and weighed to develop a baseline measurement for each process area throughout the facility.

Once the wastes were collected from each process, information was obtained from material safety data sheets (MSDS) to identify the ingredients of chemicals used in each process. This information was used to determine whether or not the chemicals were classified as hazardous.

Reviewing Hazardous Waste Regulations

Applicable hazardous waste regulations that affected the identified chemicals (found in Chapter 7045 of the Minnesota Hazardous Waste Rules) were reviewed, and interpretation of these rules was gathered from telephone interviews with staff from the Minnesota Pollution Control Agency (MPCA).

After reviewing MSDS and regulatory information and consulting with MPCA staff, the intern concluded that only materials that came in contact with certain F-listed chemicals (mostly solvents) required disposal as “Type A” hazardous waste. This verified the earlier theory that many of the contaminated materials placed in the “Type A” containers were unnecessarily being disposed of as hazardous waste.

Developing a Procedure for Segregating Hazardous from Nonhazardous Wastes

Based on the information gathered on the hazardous process chemicals, the intern developed a simple method for properly segregating the hazardous from the nonhazardous wastes.

First, containers of hazardous chemicals were clearly marked with the letter “A” using adhesive labels. The “A” indicated that the containers contained hazardous chemicals and any materials that came in contact with these chemicals must be disposed of in the “Type A” hazardous waste container. All other nonhazardous contaminated materials (that did not come into contact with “Type A” chemicals) were placed in separate waste containers.

The new labeling procedure was tested in one process area before it was implemented in other areas. During the test process, employees received training on the new labeling and waste segregation procedure. All the waste collected in “Type A” containers was measured and compared to the previously collected baseline data.

By the conclusion of the project, this procedure had been implemented in almost all other process areas where “Type A” wastes were generated. Employee training sessions for using the new labeling procedure were held in each process area during regularly scheduled employee meetings. Data on the amount of “Type A” hazardous waste also was collected in the other process areas and compared to baseline data.


According to data gathered after the labeling procedure was implemented, proper waste segregation through the use of a simple container-labeling procedure could potentially reduce hazardous waste by over 85 percent. This reduction would result in an annual cost savings of over $15,000 for the entire facility, and in reclassifying Fisher-Rosemount as a small quantity hazardous waste generator. In addition to the ease of implementation and cost savings, the capital cost to implement this procedure was minimal. Fisher-Rosemount has now incorporated the labeling procedure into its employee training materials.

The intern suggested that all chemicals being considered for use by Fisher-Rosemount be reviewed before they are purchased to determine if they would cause process materials to become hazardous on contact. By doing this pre-purchase review, Fisher-Rosemount would have the opportunity to find nonhazardous substitutes before purchasing chemicals. Fisher-Rosemount has since changed its pre-purchase agreement to require reviewing hazardous material content before chemicals are purchased.

This project was conducted in 1994 by MnTAP intern Jeff Mortensen, a chemical engineering student at the University of Minnesota, Duluth.