OBJECTIVE: This study explored the association between ethylene oxide exposure, a human carcinogen, and serum neurofilament light (sNfL) levels, a potential biomarker for neurological disorders, using National Health and Nutrition Examination Survey (NHANES). METHODS: We conducted a cross-sectional study, focusing on sNfL levels, ethylene oxide exposure, socio-demographics, and comorbidities. Multiple regressions and restricted cubic spline (RCS) analyses assessed the relationship between ethylene oxide and ln-transformed sNfL levels, with stratified analyses for subgroups. RESULTS: Among 641 participants, those in the highest ln(sNfL) quartile had higher ethylene oxide levels, were older, and had more diabetes, cancer, and heart diseases. Ethylene oxide exposure correlated positively with ln(sNfL) levels, especially among older adults, women, and non-Hispanic Whites. CONCLUSION: Ethylene oxide exposure is positively associated with elevated sNfL levels, especially in older adults, women, and non-Hispanic Whites, indicating its potential impact on neurological biomarkers.