Traditional teaching and training used to be set up for information to be 'handed down' from a teacher or subject matter expert, and most of the communication was one-way. It's probably the least effective way for people to learn and typically produces little transformation of behaviours or understanding, to say nothing of engaging and motivating learners.
As a general tip, most of the people we are working with in these situations are more accustomed to actively DOING things rather than sitting passively and being talked at, so the first thing would be to look for ways to make training more active. There are SO many possibilities with a bit of creative thinking! The more active and the more novel the activities, the greater impact of learning.
Making content more active can be as simple as doing matching or organising activities with cards. Or you can post photos on the walls and get people to move around the room in pairs or small groups with instructions to identify something in the photo - e.g., hazards, PPE, safety equipment, etc.
A simple review can be done standing up in a circle with a hackysack (or something that won't injure anyone and won't readily roll away!), and each person has to name one thing related to the content, then pass the hackysack to someone else, until everyone has had a turn.
With bigger groups, I would split into two teams, that line up beside each other, and I have a set of questions to ask. If they get their question right, they get a point. If they get it wrong or don't know the answer, the other team can have a go. After the person at the front has answered, they go to the back of the queue. Depending on the size of the group, they may cycle through more than one question per person. This activity offers a multi-sensory review, and also you can coach people by asking more questions if their answers are not quite complete. I would write the score as hash marks on a whiteboard, or you can have a bowl or plate for each team and place a chocolate on their plate for every correct answer.
For adult learners, it works a lot more effectively to facilitate discussion and ask questions to get people to explain in their own words, which reinforces that they KNOW that they know the important points. Find out what they know already, then reinforce and recognise them for that. Then you can ask more questions to get them to fill in any gaps.
From a neuroscience point of view, one of the most effective ways of getting learners engaged is to start with a carefully designed activity that isn't directly tied to the subject matter until after they have finished the activity. That's kind of hard to explain here! But as an example, I often start with a common game activity where I can reasonably predict certain outcomes or behaviours, which I can then use to make points that relate to the subject we are going to talk about. They then have an internalised experience of the concept, which gives them some useful context for the information that follows. I do this when I want people to understand concepts like hazard ID and why we have a SMS, which can otherwise be quite abstract for some people.
I hope that is some help - this is such a vast area of possibilities. I have done a lot of training on this, and still a lot of what I do is just trying things, and often an idea just comes to me when I am preparing.
You can also Google Dr Rich Allen and The Power to Train - I think he has a blog with a lot of good ideas for making training more active. He was my very first trainer on accelerated learning and adult learning, and I remember one of his early pieces of advice to me was that if I was enjoying myself, my audience would too. If I am bored, they will be bored as well.