It's important to try to use images in your safety training that reflect a diverse population. Specific images related to safety can be hard to find in the first place but trying to find safety images that reflect diversity can be almost impossible. The Noun project (a great source for icons for your training materials) has a new set of icons that show women in leadership and STEM positions. I applaud their efforts! If you want to check out or download the icons, see the link below.
Learner Personas are fictitious but realistic profiles, based on actual data, of the individuals you expect to attend your training classes. Your learner persona will have a name, age, gender and maybe some details about their life and what motivates them. Finding a photo of this learner persona and keeping it in front of you as you develop and prepare training materials can help keep you on target and help make sure training materials are going to be right for your intended audience. Sometimes, you will need to develop several personas if you have a wide variety of people in a class.