Step 4: Assess & Compare Alternatives
Systematically comparing the hazard, cost, and performance of different alternatives will enable you to make an informed decision. This step will help you assess and compare alternatives.
To prioritize alternatives for further assessment, consider:
- What are the performance requirements of the chemical or process?
- Do specific alternatives present a high risk to worker safety and health?
When assessing and comparing alternatives, consider:
- What health and safety criteria (toxicological and physical properties) need to be compared?
- Will workers experience changes to the performance of their work tasks when using the alternative, including any changes to the use of engineering controls, administrative controls, and PPE? Will workers experience changes in exposure when using the alternative? Will these changes present new/different hazards to workers?
- What performance criteria need to be compared?
- What costs need to be compared?
Once alternatives are identified, it is often necessary to prioritize them for further assessment. Focusing the work on the most promising alternatives is an effective way to use limited resources and avoid unnecessary research and evaluation.
Prioritizing alternatives based first on performance can help to narrow the scope of alternatives to those that have the potential to be effectively implemented in the workplace while maintaining process and product quality. To identify performance requirements for the chemical, material, or product that you are looking to replace, the planning team should consider what the chemical, material, or product needs to do and whether there are specific technical and engineering design constraints. Other functional requirements, such as quality criteria and customer or legal requirements for technical acceptability should also be considered.
Before further evaluating your options, you may also consider deprioritizing those alternatives that may result in new hazards or will not substantially improve worker safety and health. You can use existing restricted substances lists, authoritative lists of priority chemicals, and lists of chemicals of concern to rapidly identify alternatives that present worker safety and health concerns, are inconsistent with company goals, or may be subject to legal or consumer restrictions. While these options should not be the first you evaluate, they should not be completely eliminated from consideration. If you find, after further research and evaluation, that none of your first choice alternatives will work, you may decide to reconsider those options that, while having some concerns, could still be safer and healthier for workers in a particular application.
After identifying the most promising alternatives, the hazard, performance, and cost of each alternative should be assessed and compared. Selecting the relevant hazard criteria is the first step of your evaluation. To improve worker health and safety, some hazards you might consider for your evaluation include:
Acute Health Hazards
- Acute toxicity
- Eye damage
- Skin damage
- Sensitization (e.g., skin, respiratory)
- Oxidizing properties
- Pyrophoric properties
Chronic Health Hazards
- Chronic Toxicity
- Target Organ Toxicity
- Reproductive Toxicity
- Developmental Toxicity
- Endocrine Disruption
- Immune System Effects
- Physical form of the chemical
- Procedural hazards (e.g., open process, direct skin contact)
- Ergonomic hazards
- Noise hazards
- Vibration hazards
Several existing resources identify hazards that could be included in your evaluation. SUBSPORT's compilation of hazard criteria (health, environmental, and physical) provides information about which characteristics are associated with substances of concern. The EPA's Design for the Environment Safer Product Labeling Program has also developed hazard criteria for chemicals used in formulated products. The Massachusetts Toxics Use Reduction Institute's P2OASys Tool provides hazard criteria relevant to chemical, material, and process changes in the workplace.
As part of the hazard assessment, it is also important to understand whether alternatives will significantly change working conditions (i.e., the way in which the chemical is used by workers or the way in which workers are exposed to the chemical). This will allow you to identify any additional hazards the alternatives may present to workers. Be sure to consider upstream or downstream hazards to workers – in disassembly, making the new chemical, etc.
A number of tools are available to help you rapidly assess and compare health and physical hazards of identified alternatives. The Column Model, the Quick Chemical Assessment Tool, and the Green Screen™ can help assess and compare health, physical, and environmental hazards of identified alternatives.
Comparative chemical hazard assessment methods and tools rely on the collection of data from a variety of sources. The U.S. EPA DfE's Alternatives Assessment Criteria *(PDF) document provides information on data quality considerations in evaluating and comparing chemical hazards and Clean Production Action's Green Screen™ Tool identifies authoritative and screening data sources for each endpoint evaluated in the tool. While these resources can help you locate hazard information that is readily accessible, there are many chemicals for which this type of information is unavailable. In these cases, suppliers can also be a critical source of hazard information.
The Column Model
The Institute for Occupational Safety and Health of the German Federation of Institutions for Statutory Accident Insurance and Prevention (IFA) developed the Column Model to help small and medium-sized businesses assess substitute substances on the basis of just a small amount of information derived from safety data sheets. The model is based on six hazard categories (acute health hazards, chronic health hazards, fire and explosion hazards, environmental hazards, exposure potential, and process hazards), which are divided into different risk levels, ranked from negligible to very high. Users identify the risk level for each substance using the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) hazard classifications and information about how the substance is used. Preferred substitutes are then identified by comparing the risk levels in each of the hazard categories. In most situations, alternatives do not have the lowest risk level in all hazard categories. Users must decide which potential hazards are more relevant for the workplace where the product is used, taking into consideration the possibilities to control or manage the different risks.
The Quick Chemical Hazard Assessment (QCAT)
Developed by the Washington Department of Ecology, the Quick Chemical Assessment Tool (QCAT) is designed to help small and medium-sized businesses evaluate hazards associated with alternatives to toxic chemicals. QCAT uses a subset of nine high priority hazard endpoints (6 human health effects endpoints, persistence, bioaccumulation, and acute aquatic toxicity) to identify a level of concern for each chemical being evaluated. This evaluation places chemicals along a continuum of concern and assigns a chemical one of four possible grades (A, B, C, F). These results provide a quick and easy method to identify chemicals that are equally or more toxic than the chemical being reviewed, allowing users to leverage limited resources to rapidly identify chemicals that are not viable alternatives to the chemical being assessed.
The Pollution Prevention Options Analysis System (P2OASys)
The Toxics Use Reduction Institute developed the Pollution Prevention Options Analysis System (P2OASys) to help companies determine whether the options they are considering to replace chemicals, materials, products, or processes of concern may have unforeseen negative worker, public health, or environmental impacts. Companies using P2OASys input both quantitative and qualitative data on the chemical toxicity, ecological effects, physical properties, and changes in work organization as a result of the proposed option. The tool arrays data on a range of hazards and the chemical under evaluation receives a score, based on embedded formulae in an excel spreadsheet, for each type of hazard that indicates very low to very high risk. These scores can then be combined with other information sources and professional expertise to make decisions on the selection and adoption of alternatives.
Next, alternatives should be assessed and compared based on their performance. Selecting the relevant criteria is the first step of your evaluation. To ensure the alternative performs well, some performance parameters you might consider for your evaluation include:
- Water solubility
- Boiling point/melting point
- Flash point
- Vapor pressure
- Maintenance requirements
- Energy consumption
- Equipment requirements
- Tensile strength
- Tear strength
- Flame retardancy
- Resistance to shock/vibration
- Noise level
- Operating temperature
The relevant parameters may vary greatly from one application to another. Engaging the team, and any other workers, product designers, and production engineers, can help identify performance needs, as well as technical and engineering design restraints. You may also need to consult with suppliers and customers not only to identify the critical parameters for evaluation, but also to gather information about the performance of alternatives under evaluation.
Toxics Use Reduction Institute's Technical Performance Evaluation
As part of its 2006 Five Chemical Study, the Massachusetts Toxics Use Reduction Institute developed a model for evaluating the technical performance of alternative chemicals, materials, products, and processes. The study identified application-specific performance parameters that were required for each use of the chemicals under evaluation – including longevity, key performance requirements, key physical characteristics and key quality parameters. While applicable performance requirements vary greatly between uses, this evaluation method provides a good starting point for identifying criteria that should be considered.
Adapted from TURI Alternatives Assessment Process Guidance.
Finally, alternatives should be assessed and compared based on their cost. While a full cost-benefit analysis of all the alternative options is quite costly and not essential, it is important to thoroughly consider relevant cost impacts, both positive and negative, on your company. Completing such an economic analysis will also help you make the business case for transitioning to safer alternatives. Some costs and benefits that you might consider in your evaluation include:
- Capital expenditures
- Operating costs
- Material costs
- Maintenance costs
- Supervision and administrative costs
- Regulatory compliance costs
- Worker health and safety costs (PPE, lost employee time, etc.)
- Waste management expenditures, including hazardous waste disposal costs
- Insurance, rent, taxes
- Penalties and fines
- Personal injury
- Worker Compensation
- Property damage
- Clean-up costs
- Natural resources damage
Less Tangible Benefits
- Increased sales due to improved product quality, enhanced public image, consumer trust in greener products, or other effects
- Reduced health maintenance costs due to a safer work environment
- Improved worker productivity due to cleaner working conditions
- Increased worker productivity due to improved employee relations
European Commission's Cost Assessment Methodology
The European Commission's Guidance on Minimizing Chemical Risk to Workers' Health and Safety Through Substitution provides a detailed table to help small and medium-sized businesses identify costs to take into account. The table includes parameters for evaluating material costs, equipment costs, safety costs, time related costs, waste costs, and the costs of risk. This table is also useful for presenting the impacts and consequences of a substitution to management.
Green Seal. GS-37 Cleaning Products for Industrial and Institutional Use. This standard establishes requirements for industrial and institutional cleaning products and includes product performance requirements and environmental and health considerations.
SUBSPORT. Identifying Substances of Concern. This resource presents an overview of the criteria and their definitions that are most used by different sources to identify substances of concern.
U.S. Environmental Protection Agency. DfE's Standard and Criteria for Safer Chemical Ingredients. This standard includes hazard criteria used to define safer chemical ingredients for several categories of formulated products.
Comparative Chemical Hazard Assessment Tools
Clean Production Action. GreenScreen™ for Safer Chemicals. This is a methodology for comparative chemical hazard assessment that can be used for identifying chemicals of high concern and safer alternatives.
German Institute for Occupational Safety and Health. Column Model for Chemical Substitutes. This tool helps businesses make a quick comparison between the risks of different substances and preparations based on information found on a Safety Data Sheet.
Massachusetts Toxics Use Reduction Institute. Pollution Prevention Options Assessment System (P2OASys). This tool helps companies assess the potential environmental, worker, and public health impacts of alternative technologies aimed at reducing toxics use.
Washington Department of Ecology. Quick Chemical Assessment Tool (QCAT). This is a simplified assessment tool used to evaluate hazards associated with alternatives to toxic chemicals.
Massachusetts Toxics Use Reduction Institute. Alternatives Assessment Process Guidance. This guidance document provides a methodology for assessing and comparing the performance of alternatives.
European Commission. Minimizing Chemical Risk to Workers' Health and Safety Through Substitution. Appendix 6 of this guidance document provides a detailed table to help small and medium-sized businesses identify costs to take into account. This table is also useful for presenting the impacts and consequences of a substitution to management.
Massachusetts Toxics Use Reduction Institute. Alternatives Assessment Process Guidance. This guidance document provides a methodology for assessing and comparing the cost of alternatives.
Ontario Toxics Use Reduction Program. Reference Tool for Assessing Safer Chemical Alternatives. *(PDF) This guidance document provides information on completing an economics assessment as part of an alternatives assessment.
U.S. Environmental Protection Agency. Cleaner Technology Substitutes Assessment Methodology. *(PDF) This guidance document provides a methodology for assessing and comparing the cost of alternatives.