*2.1. EDC Footprint Tool Development*

The EDC footprint calculator was developed by conducting a review of existing databases and papers to identify the masses of EDCs in various commonly used PCPs. The three product categories that were selected are health and beauty products, household cleaning products, and laundry products. The individual products included in the health and beauty products category are hand soap, hand sanitizer, bar soap, body wash, shampoo, conditioner, shaving cream, body lotion, face lotion, facial cleanser, toothpaste, deodorant, hair products, lipstick, mascara, foundation, nail polish, sunscreen, and perfume/cologne. The products included in the household cleaning products category are surface cleaner, floor cleaner, glass cleaner, bathtub and tile cleaner, toilet bowl cleaner, air freshener, carpet cleaner, floor polish/wax, dishwasher detergent, and dish liquid. The individual products in the laundry category are laundry bleach, laundry detergent, and dryer sheets. The EDCs that can be found in these products and are included in the calculator are outlined in Table 1. Although pharmaceuticals are often grouped with personal care products as sources of EDCs, we decided not to include them and instead focused only on products used for personal hygiene and other household cleaning activities, as these are likely to be the dominant contributors to a user's total EDC footprint and are less intrusive than prompting a user to input potentially sensitive or confidential medical information.

**Table 1.** Categories of endocrine-disrupting compounds (EDCs) and specific compounds within each category that were included in the EDC footprint calculator.


Numbers used in the calculator were taken as an average of the results in the Dodson et al. [27] study when the concentrations were <1000 μg/g. For the products containing EDCs above 1000 μg/g, concentrations were obtained from the Consumer Product Information Database (CPID) [28]. The concentrations of EDCs in perfume and cologne were further improved using concentrations reported by Peters [29]. This report analyzed phthalates and fragrances in 36 perfume products.

The EDC footprint calculator was initially developed in Microsoft® ExcelTM as a downloadable spreadsheet-based tool (the blank version is shown in Figure 1). The calculator was divided into sections for each of the three major product categories: cleaners, laundry, and health and beauty. The user interface column accepts input in milliliters (mL) for liquid products and grams (g) for solid products (shown in green on the calculator; Figure 1). If a user has multiple containers of a product (e.g., two tubes of toothpaste), the user can add the quantities together and enter a total amount in the appropriate column. The calculator uses the information (i.e., masses and volumes) inserted by the user and multiplies the

concentration of EDCs (and the density of the product if the input is in mL) to estimate the mass (in mg) of EDCs in each product:

$$\times \frac{\mu \text{g}\_{\text{EDC}}}{\text{g}\_{\text{product}}} \times y \frac{\text{g}\_{\text{product}}}{\text{cm}^3\_{\text{product}}} \times z \text{ } m\text{L}\_{\text{product}} \times 1 \frac{\text{cm}^3\_{\text{product}}}{\text{mL}\_{\text{product}}} \times \frac{1 \text{ mg}\_{\text{EDC}}}{1000 \text{ }\mu \text{g}\_{\text{EDC}}} = \text{mg}\_{\text{EDC}} \tag{1}$$

where *x* is the concentration of EDC in a product from the existing literature [27–29], *y* is the density of that product from CPID [28], and *z* is the volume of product the user entered. The calculator then sums the mass of EDCs calculated for each product and determines the total mass (in g) of EDCs estimated to be in all of the products the user entered. This total mas is the EDC footprint and is shown in red in the bottom right corner of the calculator (Figure 1). The footprint tool was made publicly available through Penn State Extension [30].


**Figure 1.** Endocrine-disrupting compound (EDC) footprint calculator user interface. User input is accepted in either volume (mL) or mass (g). The calculator then calculates and displays the estimated mass of EDCs in each product. The total EDC footprint for all products entered by the user is displayed in red on the bottom right side of the tool's interface.

To facilitate a more user-friendly version of the calculator that did not require a Microsoft® ExcelTM license, we developed a web-based version of the tool using QualtricsTM (Qualtrics, Provo, UT, USA). This version made the calculator more widely accessible to a broader audience since it does not require users to have the software or the technical skills to use it. Further, the online Qualtrics version allows data to be collected anonymously, enabling research to be conducted to better understand what typical ranges of EDC footprints are for households at various scales from local to regional to national and potentially even

global. Between 2018 and 2022, the EDC footprint tool has been used more than 1400 times, with users in the United States, Mexico, Canada, India, Taiwan, and Europe.

The tool provides several graphical outputs to assist the user in interpreting the results. The first visual output is a pie chart that provides the percent contribution of each of the three product categories to the total EDC footprint, enabling the user to easily assess how much of the total footprint is from products in the health and beauty, cleaners, and laundry categories. The second visual output is a pie chart that provides the percent contribution of each EDC category to the overall EDC footprint. This allows the user to easily assess the percent contribution of the following categories to the overall EDC footprint: UV filters, cyclosiloxanes, glycol ethers, fragrances, alkylphenols, ethanolamines, antimicrobials, BPA, phthalates, and parabens (see Table 1 for the specific chemicals included in each of these categories). Finally, the calculator ranks the percent contribution of each product to the overall EDC footprint and visualizes the contribution (mass) of the top 10 products in a bar chart. This chart is intended to help the user determine which specific products are contributing the most to the total EDC footprint, thereby providing the user with easily accessible information regarding which products have the highest potential to reduce the user's EDC footprint if they were to be exchanged for a "greener" product.

A "green" version of the EDC footprint calculator was developed in the same manner described for the original version of the calculator; however, it has not yet been made publicly available. This "green" version is based on EDC concentrations for products marketed as "eco-friendly" or "green" in the study by Dodson et al. [27]. Specifically, we replaced the original concentrations of each EDC in each product reported by Dodson et al. [27] with the concentrations of the products that Dodson et al. [27] reported for the "green" products.

It should be noted that the EDC footprints generated from this tool are based on the products in a household at the time the footprint tool was used and is not meant to provide an estimate of usage of these products over a specific amount of time. For example, some products, such as hand soap, are likely used more frequently than other products. We did not attempt to capture the time frame over which the products contributing to the footprint would be consumed. Rather, at the scale of an individual household, the results are meant to serve the following purposes: (1) informing the user of the total EDC footprint of the products in the household at the time the calculator was used; (2) visualization of the results to enable the user to understand the contribution of products used in each of the three product categories to the total footprint; (3) determination of the individual products contributing the most to the total footprint; and (4) understanding the individual ingredients categorized as EDCs that are present in the products used in the household. The user is then empowered with the information necessary to make changes in product selection to reduce the household's footprint through product selection that avoids specific ingredients or by replacing the top-ranking products with greener alternatives. We recognize that a footprint could be reduced by having less of a product in the household at the time the footprint calculator is used, such that someone who buys products in bulk may have a higher "snapshot" footprint than someone who buys products as needed; however, the user knows what the shopping habits of the household are and can interpret the results in the context of that knowledge (e.g., a higher snapshot footprint does not necessarily mean a higher annual footprint).
