The development of a tool for measuring food safety literacy among working age population

Objective Food safety literacy among working-age adults is increasingly recognized as a key determinant of safe food handling behaviors and, indirectly, foodborne disease risk. However, existing measurement approaches are dominated by knowledge-based or knowledge–attitude–practice instruments, which often fail to capture the broader competencies required for food safety decision-making in real-world food environments. This study aimed to develop and validate a multidimensional food safety literacy measurement tool specifically designed for working-age adults. Methods A cross-sectional instrument development study was conducted among 480 working-age adults (25–60 years) from 12 provinces in Thailand where Food Safety Mobile Units operate. The instrument was developed based on health literacy and food literacy frameworks and initially comprised five domains: basic knowledge, interactive skills, behaviors, and judgment, along with personal and contextual factors. Content validity was evaluated using the index of item–objective congruence. Internal consistency reliability, item difficulty, and discrimination indices were assessed. Construct validity was examined using exploratory factor analysis with principal component extraction and varimax rotation. Results The final instrument consisted of 32 items and demonstrated high internal consistency (Cronbach’s α = 0.902). Exploratory factor analysis identified six distinct components: (1) hygienic food storage and cooking; (2) food safety behaviors; (3) food safety communication and social interaction skills; (4) knowledge of food contamination hazards; (5) consumer rights and food safety information; and (6) food safety judgment and decision-making. These factors explained 65.15% of the total variance, with all retained items showing acceptable factor loadings and communalities. Conclusions The developed food safety literacy instrument demonstrates strong psychometric properties and captures functional, interactive, behavioral, and critical dimensions of food safety literacy relevant to working-age adults. This tool offers a comprehensive approach for assessing food safety literacy at the population level and supports intervention development, and policy evaluation aimed at improving food safety outcomes.