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Lean Manufacturing and Environment

The Lean and Chemicals Toolkit

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Chapter 2: Overview of Chemical Use and Lean

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Understanding chemicals is an important step when undertaking methods to reduce chemical use and waste.

Definition of Chemical Waste

Key TermAs discussed in Chapter 1, chemical waste is any unnecessary or excess use of a chemical, or a chemical substance that could harm human health or the environment when released to the air, water, or land. Chemical waste is a subset of “environmental waste” described in EPA’s Lean and Environment Toolkit.

Many chemical wastes can be classified as hazardous waste. Hazardous wastes are the types of waste that can cause the most damage to human health and the environment. (1) Hazardous wastes can be liquids, solids, gases, or sludge. They can be discarded commercial products, such as cleaning fluids or pesticides, or the by-products of manufacturing processes.

Box 5 lists examples of chemical wastes. While containers used to store hazardous waste have easy-to-spot indicators of chemical waste, other sources may be more difficult to identify, including chemical waste that may be hidden in established processes. Other chemical wastes include excess mixed or unmixed chemicals and materials contaminated with chemicals.

Example of Chemical Wastes (Box 5)
  • Chemicals that can no longer be used for their intended use (e.g. aged or surplus inventory)

  • Mislabeled or unlabeled chemicals

  • Abandoned chemicals

  • Material in deteriorating or damaged containers

  • Residuals in chemical containers

  • Diluted solutions containing hazardous chemicals

  • Used photographic fixer and developer

  • Debris contaminated with a hazardous material (rags, paper towels, lab diapers, gloves, etc.)

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Understanding the Dangers of Chemicals

Many types of chemicals are hazardous. For safety and security it is important to be able to recognize any dangers involved in storing and using certain chemicals. It is also important to know about chemical characteristics when disposing of chemicals to ensure that those wastes are disposed of properly. Hazardous chemical warning signs exist to warn people of the dangers involved in using certain chemicals. Figure 1 describes several common chemical warning signs.

Chemical Warning Signs (Figure 1)

ignitable symbolIgnitable chemicals generally are liquids with flash points below
60°C or 140°F.

ignitable symbolReactive chemicals ignite or create poisonous vapors when mixed with other products or can explode when exposed to heat, air, water, or shock.

ignitable symbolCorrosive chemicals are generally aqueous wastes with as pH less than or equal to 2.0 or greater than or equal to 12.5.

ignitable symbolToxic chemicals may cause long-term illness (such as cancer). Pesticides, paint thinners, many auto products, and some cleaners are toxic.

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New ToolAnother common system for identifying chemical hazards is the U.S. National Fire Protection Association (NFPA) system. NFPA chemical hazard warning labels are attached to the containers with the chemicals. Although it looks simple, an NFPA label carries a lot of important information about a chemical. NFPA labels are color coded; each color on the label represents a different type of hazard. The system also uses a numerical rating system. Zero represents little to no danger, while a rating of four represents the greatest danger.

Figure 2 contains an example of a label from the NFPA system for the chemical diborane. According to the rating system, diborane is extremely flammable and reactive and presents a serious health hazard.

National Fire Protection Association Chemical Lable Example (Figure 2)
ignitable symbol

Blue = Health hazard
Red = Fire hazard
Yellow = Reactivity hazard
White = Special hazard

0 = minimal hazard
1 = slight hazard
2 = moderate hazard
3 = serious hazard
4 = severe hazard


Examples of Hazardous Chemicals

EPA’s National Partnership for Environmental Priorities (NPEP) Program has identified 31 chemicals and metals that are particularly hazardous to human health and the environment. NPEP is an EPA partnership program in which public and private organizations partner with EPA to reduce or discontinue the use of these 31 chemicals (for more information, see http://www.epa.gov/npep). Table 1 lists the 31 Priority Chemicals, which include organic compounds and metal compounds.

EPAS List of 31 Priority Chemicals (Table 1)
Organic Compounds
4-Bromophenyl phenyl ether
Endosulfan, alpha & Endosulfan, beta* 
Heptachlor & Heptachlor epoxide*
Hexachlorocyclohexane, (gamma-Lindane)
Pentachloronitrobenzene (Quintozene)
Polycyclic Aromatic Compounds (PACs) / PAH Group (as defined in TRI)
Polychlorinated Biphenyls (PCBs)
Metals and Metal Compounds
* Considered one chemical on this list

Source: US EPA, National Partnership for Environmental Priorities, www.epa.gov/npep

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How to Learn More about Chemicals

Understanding the types of chemicals your business uses and the hazards associated with them is the first step to take when deciding how and where to eliminate chemical wastes. There are a variety of resources available for learning more about chemicals and their characteristics. Two important resources include Material Safety Data Sheets and a Pocket Guide to Chemical Hazards.

Key PointMaterial Safety Data Sheets (MSDS) are an important resource and safety tool for workers who handle chemicals. MSDSs are designed to provide both workers and emergency personnel with the proper procedures for handling or working with a particular substance. The Occupational Health and Safety Administration (OSHA) requires that MSDS forms be available to all employees working with chemicals. MSDSs include information on physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill/leak procedures. These are of particular use if a spill or accident occurs. Appendix B contains a template for a Material Safety Data Sheet.

Key PointAnother tool for identifying and understanding hazardous chemicals is a pocket guide to chemical hazards issued by the National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control and Prevention (CDC). The NIOSH Pocket Guide to Chemical Hazards (NPG) is a source of general industrial hygiene information on several hundred chemicals for workers, employers, and occupational health professionals. The NPG does not contain an analysis of all pertinent data; instead it presents key information and data in abbreviated or tabular form for chemicals or substance groupings (e.g., cyanides, fluorides, manganese compounds) that are found in the work environment. The Pocket Guide includes the following information:

  • NIOSH Recommended Exposure Limits
  • Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits
  • A physical description of the agent with chemical and physical properties
  • Measurement method
  • Personal protection and sanitation recommendations
  • Respirator recommendations
  • Information on health hazards including route, symptoms, first aid, and target organ information
Appendix A describes additional chemical resources, including resources for identifying substitutes for hazardous chemicals. Furthermore, Chapter 6 (Lean Product and Process Design Methods) describes strategies and tools for designing products and processes that use less hazardous chemicals.

The Chemical Lifecycle

Key PointThe use of chemicals for production is just one part of the “lifecycle” of a chemical. The chemical lifecycle includes all the activities involved in the manufacturing, use, storage, disposal, and possible re-use of chemical substances. Figure 3 outlines the stages of the chemical lifecycle.

Chemical Lifecycle (Figure 3)

Figure 3

As with typical product “value streams” (which generally focus on the “use” or “manufacturing” steps), there are non-value added activities (wastes) associated with each step in the chemical lifecycle. The following chapters in this toolkit describe a variety of ways that Lean methods can be used to identify and reduce chemical wastes. Chapters 3, 4, and 5 focus on reducing wastes in the “inventory,” “use,” and “waste” stages of the chemical lifecycle. Chapter 6, with its focus on product design, covers strategies that affect multiple stages in the lifecycle, including chemical manufacturing and the selection of chemicals.

To Consider
  • What types of chemicals does your facility use and/or produce?
  • Are the chemicals well marked and easy to identify?
  • Do you know the hazards associated with those chemicals?
  • How much money does your facility spend purchasing chemicals?  How much of those chemicals are thrown away before being used (e.g., if they expire or go off-specification)?
  • How much money does your facility spend on hazardous wastes? (Consider costs for purchasing raw materials that end up in hazardous waste streams as well as costs to dispose of the wastes.)
  • Who makes decisions involving chemical use at your company?

1. See the disclaimer regarding the definitions of wastes used in this toolkit.


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