Understanding BEES Scores

Here are the impacts that make up the BEES Environmental and Economic Performance Scores. Click on any impact or score for more information on its meaning and use in the BioPreferred context.

BEES results are provided to empower the procuring official to consider environmental and economic performance in identifying the product that best meets the Federal agency’s needs. By scoring products across a comprehensive range of environmental and economic impacts, BEES facilitates purchasing that takes into account the trade-offs often necessary to achieve a genuine reduction in these impacts, rather than a simple shift of impact. For example, “green” purchasing based on minimizing the global warming impact alone does not account for the fact that global warming may have been reduced at the expense of other impacts. And a short-lived, low first-cost product is often not the most cost-effective alternative. A higher first cost may be justified many times over for a durable, maintenance-free product.

While the degree to which life-cycle environmental and economic performance are incorporated into the procurement system is left up to each agency, BioPreferred reports BEES performance results for the types of biobased products that would fall within each designated item grouping. Agencies are encouraged to request BEES results from manufacturers of fossil fuel-based products to facilitate direct comparison of life-cycle performance within a designated item. BEES results for fossil fuel-based products can be obtained by manufacturers through the NIST BEES Please program.

While procurement officials are encouraged to consider life cycle costs and environmental impacts when appropriate in the context of a specific procurement, BioPreferred is not in a position to establish specific qualifying standards—such as maximum allowable BEES scores—for all possible products for all procurements. Moreover, by reporting results for all impacts contributing to the BEES performance scores, BioPreferred provides agencies the flexibility to place more or less importance on contributing impacts than assigned by BEES. For more on the importance BEES places on contributing impacts, see pages 26-32 of the BEES Technical Manual.

Environmental Performance Score

The BEES Environmental Performance Score combines product performance across all 12 environmental impacts into a single score. The lower the score, the better is the product’s overall environmental performance.

The BEES Environmental Performance Score indicates the share of annual per capita U.S. environmental impacts attributable to the product. A score of 0.0130, for example, means the production and consumption of a unit of the product is estimated to represent 0.0130 percent of average annual U.S. per capita contributions to environmental impacts.

Global Warming is due to emissions generated by humankind that keep the earth’s surface warmer than it would be otherwise. The BEES Global Warming Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Acidification damages trees, soil, buildings, animals, and humans. Commonly referred to as “acid rain,” its principal human source is fossil fuel and biomass combustion. The BEES Acidification Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Eutrophication is the addition of mineral nutrients to the soil or water, which in large quantities results in generally undesirable shifts in the number of species in ecosystems and a reduction in ecological diversity. The BEES Eutrophication Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Fossil Fuel Depletion occurs when these resources are consumed at rates faster than nature renews them. The BEES Fossil Fuel Depletion Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Indoor Air Quality suffers when products release pollutants indoors during their use. The BEES Indoor Air Quality Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Habitat Alteration measures the potential for land use by humans to lead to undesirable changes in habitats. The BEES Habitat Alteration Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Water Intake can be problematic in areas where water is scarce, such as the Western United States. The BEES Water Intake Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Criteria Air Pollutants arise from many activities including combustion, vehicle operation, power generation, materials handling, and crushing and grinding operations. They include coarse particles known to aggravate respiratory conditions such as asthma, and fine particles that can lead to more serious respiratory symptoms and disease. The BEES Criteria Air Pollutants Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Human Health effects can arise from exposure to industrial and natural substances, and range from transient irritation to permanent disability and even death. The BEES Human Health Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

BioPreferred requires reporting of the details underlying the BEES Human Health Scores, so a Human Health by Sorted Flows report is included with the BEES results. In assessing human health, BEES tracks more than 200 flows to air “(a)” and water “(w)” associated with cancer and other human health issues. The five flows with the largest contributions to the BEES Human Health Score are displayed in the report, with all others combined and reported as “All Other Flows.” These values are reported in grams of toluene per unit of product. Most result from electricity production that occurs outside the gates of the biobased product manufacturing facility. While the values may look large, the average U.S. resident is responsible for over 158 million grams of toluene-equivalent releases per year. So when you put the BEES Human Health Scores into context (like they are in the Environmental Performance report), they're not as large as they may first appear.

Smog forms under certain climatic conditions when air emissions from industry and transportation are trapped at ground level where they react with sunlight. Smog leads to harmful impacts on human health and vegetation. The BEES Smog Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Ozone Depletion, or a thinning of the stratospheric ozone layer, allows more harmful short wave radiation to reach the Earth’s surface, potentially causing undesirable changes in ecosystems, agricultural productivity, skin cancer rates, and eye cataracts, among other issues. The BEES Ozone Depletion Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Ecological Toxicity measures the potential of pollutants from industrial sources to harm land- and water-based ecosystems. The BEES Ecological Toxicity Score indicates the degree to which production and consumption of the biobased product contributes to this environmental impact.

Economic Performance Score

BEES scores economic performance on the basis of a product’s life-cycle cost. The lower the life-cycle cost, the better is the product’s overall economic performance.

The life-cycle cost includes all costs associated with a product over a fixed period of time. These costs are particularly relevant for durable products such as building materials for which competing alternative products may have significantly different useful lives, maintenance and repair schedules, operating energy usage, and installation requirements. Life-cycle costing accounts for these important differences by evaluating product alternatives over the same study period.

First Costs includes costs for product purchase and, if applicable, installation.

Future Costs include costs for operation, maintenance, repair, and replacement. For consumables and other products for which no significant or quantifiable durability differences are found among competing alternatives, future costs are not calculated.

For a more technical, detailed description of the BEES product scoring system, go to the BEES Technical Manual.

BEES Scoring Changes

The August 2007 release of the BEES 4.0e software included several improvements to the BEES scoring system. These, in turn, prompted corresponding improvements to the BioPreferred BEES scoring system, beginning with Round 7 item designations:

Biobased products are credited for recently sequestered carbon.  The amount of carbon absorbed during agricultural production, technically known as “recently sequestered carbon,” is now considered a negative Global Warming flow. This leads to lower—and better—BEES Global Warming scores for biobased products. BioPreferred Rounds 1 through 6 assumed biobased products were “carbon neutral,” meaning all the carbon sequestered during agricultural production was assumed to be released over the product life cycle. The former approach is most appropriate for fuel products and products incinerated at end of life, because combustion releases nearly all sequestered carbon. Since there is very little incineration in the United States and BioPreferred does not evaluate fuel products per se, this assumption has been abandoned in favor of crediting biobased products for recently sequestered carbon.

Environmental performance is scored using an updated set of importance weights. BEES scores Environmental Performance based on a weighted average of scores across 12 environmental impacts. In May 2006, NIST convened a BEES Stakeholder Panel to develop an updated set of importance weights using a more direct approach to prioritizing diverse environmental problems. Beginning with Round 7, the updated weight set, known as the BEES Stakeholder Panel weights, is used to score Environmental Performance for BioPreferred.  For more on the BEES Stakeholder Panel activity and the EPA weights used for Rounds 1 through 6, refer to section 2.1.4 of the BEES 4.0 Technical Manual and User Guide. 

Economic performance is scored using an updated discount rate. In BEES, Economic Performance is scored using the life-cycle costing method. To compute life-cycle costs, discount rates are used to bring future costs back to their equivalent present value. Beginning with Round 7 the “real” discount rate (i.e., the rate reflecting the time value of money apart from general price inflation) used to develop BEES Economic Performance scores has been updated to the 3.0 % rate specified in 2007 by the U.S. Office of Management and Budget (OMB) for most Federal analyses. Rounds 1 through 6 used the 2002 OMB rate of 3.9 % real. The higher the discount rate, the less important are future costs.