Introduction The majority of workers are employed by small enterprises; however, small enterprises face many barriers to building and maintaining cultures of health and safety. This presentation will describe preliminary data from the evaluation of an existing community-based Total Worker Health (TWH) intervention – Health Links plus senior-level TWH leadership training – which aims to build small business capacity around health, safety and wellbeing policies and programs as well as strengthenorganisational climates.

Methods We are recruiting small businesses with fewer than 500 employees in a variety of high and low hazard industries in Colorado USA. Upon enrolment, businesses are randomised into one of two doses:

• Health Links plus senior–level TWH leadership training and

• Health Links.

Annual business- and employee-level assessments are collected.

Results Data collection began in April 2017 and we will have baseline data to share from about 100 businesses and 3500 employees. We will present a cross-sectional assessment of (1) organizational-level adoption of TWH policies and programs (2) organisational safety and health climates, and (3) worker-level health and safety outcomes.

Preliminary data from businesses enrolled in Health Links prior to the start of the study (n=145) indicates variation in level of policies and programs by business. Thus, we hypothesise that small businesses that have more TWH policies and programs have (1) more positive organisational safety and health climates, and (2) safer and healthier workers.

Discussion Little is known about small business capacity for delivering health, safety and wellbeing. Even less is known about how TWH interventions impact employee safety, health and well-being in small enterprises. This information is needed to understand how to creategeneralizable TWH interventions that can have a broad public health impact.