According to a Gallup poll released Friday, nonunion workers are far more likely then unionized workers to be content with safety and recognition at work.

“Employed Americans who report being members of labor unions are significantly less likely than nonunion employees to say they are ‘completely satisfied’ with six of 13 job aspects,” Gallup detailed. “These include workplace safety, recognition for accomplishments, flexibility of hours and job security.”

The most significant gap was shown in how workers perceive safety at work. Only 57 percent of union members expressed complete satisfaction with safety conditions compared with 73 percent of nonunionized workers. Recognition at work accounted for 35 percent of union members feeling satisfied compared to 50 percent of nonunion workers.

After that, 52 percent of unionized workers and 64 percent of nonunionized workers feel completely satisfied with the flexibility of their hours. Additionally, 45 percent of union and 58 percent of nonunion workers feel satisfied with their boss.

Gallup asserts the divide may likely be caused by the type of occupations different workers have. Low-skilled and dangerous jobs tend to have higher rates of unionization. This, as a result, is likely bringing satisfaction levels down.

“[They’re] comparatively more dangerous work environments and other such traits,” Gallup noted. “In these cases, it is likely that fraught workplace conditions helped prompt unionization in the first place and principally explain the job satisfaction differences reviewed here.”

The poll also found no statistical differences when it came to pay, vacation time, employer-sponsored retirement plans and levels of on-the-job stress. It also noted both union and nonunion workers report being very satisfied with their relationship to coworkers.