Abstract The Black identity, hair product use, and breast cancer scale (BHBS) was developed and previously validated to evaluate the relationship between identity, hair product use, and breast cancer risk for Black women. Black women are disproportionately affected by breast cancer compared to other racial/ethnic groups, with a mortality rate of 40% higher than all other groups. Endocrine Disrupting Chemicals (EDCs) are present in many hair care products and have been linked to several health issues including breast cancer. Due to these health inequities and the complexity of how cultural norms shape Black women’s hair product usage, the purpose of this study was to assess the reliability of the BHBS for intervention planning and evaluate the hazard scores of hair products used by Black women. Methods: Participants were recruited using purposive convenience sampling techniques. The 11-item BHBS includes two subscales: five items measuring sociocultural perspectives about hair and identity (S1) and six items assessing perceived breast cancer risk related to hair product use (S2). To determine reliability, the BHBS was administered twice over a three-week period with sociodemographic factors obtained in the initial data collection phase. All statistical analyses, including descriptive statistics and test-retest reliability (Pearson correlations) were conducted using SPSS version 26. The Environmental Working Group's (EWG's) Skin Deep® database was used to determine hazard scores of hair products used by participants. Products are rated on a 10-point scale with low (0-2), moderate (3-6), and high hazard (7-10) scores. Results: Twenty-three (86.9% African, African American & Caribbean; 13% multiracial) female participants completed the study. Their age ranged from 18-63 years (30.78, SD= 15.40), 47.8% reported an income of less than $25,000, and 34.8% completed some college education. Both subscales demonstrated highly significant and strong reliability (S1: r=.82, p< .001; S2: r=.88, p< .001). Participants primarily used conditioners (91.3% used wash out and 60.9% used leave-in), and professional hair dyes (34.8%). There was also a high frequency of non-use (91.3%) of do-it-yourself relaxers and hair dye kits. We evaluated 40 products across three categories including wash out conditioners, leave-in conditioners and other hair products (e.g., styling gels, shampoo, and hair oils), of which most had a moderate hazard rating of 5 denoting ingredients of health concerns (e.g., parabens, fragrance, and phenoxyethanol). Additionally, of the 22 company brands analyzed, only 10 (45%) are Black owned or founded. Conclusions: The BHBS is a valid and reliable instrument to assess sociocultural perspectives about hair, identity and perceived breast cancer risk. Black women use hair products including relaxers, hair dyes, and conditioners that contain EDCs that may be harmful to their health including risk for breast cancer. The BHBS will be used to evaluate psychosocial interventions that address the unique needs of Black women including exposure to EDCs from hair product use and breast cancer risk. Citation Format: Nicole Sarkaria, Marissa Ericson, Abigail Lopez, Dede Teteh. The hidden costs of beauty: An evaluation of breast cancer risk for Black women [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-25-09.