**1. Introduction**

In 2016, there were approximately 19.3 million workers in the United States under the age of 24, representing 13% of the total workforce [1]. For 2016, incidence rates for non-fatal injuries and illnesses were 101.9 per 10,000 Full Time Employment (FTE) compared to 100.4 for all ages [2]. Similarly, in 2014, the rates of work-related injuries treated in emergency departments for workers, aged 15–19 and 20–24 were 2.18 times and 1.76 times greater than the rate for workers 25 years of age and older [3]. According to the Census of Fatal Occupational Injuries, the average rate of fatal injuries among workers less than 18 years was 47 deaths per year from 1994 to 2013 [4]. Inexperience, lack of knowledge about workplace hazards, and a reluctance to speak up have been associated with the increase in injury rates in young workers [5–7]. Young workers do not mention safety as their main priority at work and are often not aware of their legal rights and the tasks prohibited by labor laws [8]. They are eager to please

their supervisors and may be reluctant to report injuries leading to underreporting [7,9,10], which might lead to an underestimation of the injury rates.

The Occupational Safety and Health Administration (OSHA) requires training to be a part of every employer's safety and health program to protect workers from injury and illness (OSHA, 2015). Training programs have been found to improve knowledge and awareness of workplace safety [8,11]. However, most young workers report not receiving training on worker safety and health [12]. Those that receive training state that most trainings are brief and inadequate [13] and may not include information addressing both health and safety topics [14].

Recognizing these issues among young workers, the National Institute for Occupational Safety and Health (NIOSH) developed the Youth@Work: Talking Safety classroom-based curriculum to address the needs of young workers [15]. Promoting U through Safety and Health (PUSH), a Total Worker Health® (TWH) training, expands the content of the Youth@Work curriculum to include information addressing health, safety, and communication in an online format. PUSH was developed through the Oregon Healthy Workforce Center, a NIOSH Total Worker Health® Center of Excellence [12,14,16]. Total Worker Health® is a strategy that integrates health promotion with injury prevention by looking at work as a social determinant of health. TWH focuses on job-related factors such as wages, hours of work, workload and stress levels, interactions with coworkers and supervisors, access to paid leave, and health promoting workplaces to have an impact on the wellbeing of workers [17]. Interventions addressing TWH improve workplace health effectively and more rapidly than wellness programs solely focused on health promotion [18–20].

Previously evaluated among parks and recreation workers, PUSH was found to be effective in increasing the safety and health knowledge among young workers [12]. The current study assessed the generalizability of the program among an expanded group of young workers. The main goal of the study was to assess the effectiveness of the PUSH training to increase knowledge about hazard identification, control selection, and communication between two groups of young workers using a pretest-posttest design. A second goal was to assess the likeability of the online training and to examine the impact on behavior to prepare workers to address hazards in the workplace (i.e. preparedness).
