Before assuming that elearning is the answer, consider the questions.
What is it that people MUST know? and
How can this be tested?
By concentrating more on how to check, (ie be assured that knowledge / competency exists to the level you require) it may be that the best methods of knowledge transfer become clear.
Personal opinion is that, as a profession, we try to 'train' too much, in too broad a range, yet without any real justification. What on earth is 'health & safety awareness' anyway?
Skills & knowledge needed to do a job safely, ought to be transferred through the job training. Practice, with supervision, produces competency.
Apart from fire and other 'emergency' type instruction, knowledge & skills for lifting, using machinery or plant, or working in certain environments, such as heights, yards, highways, etc. etc. ought to be within the OTJ training, which I would expect supervisors to be doing.
If there really is no resource for buying-in training, maybe that is a blessing, as it leaves only the option of structured, but delegated, competency transfer, delivered to clear objectives, (probably emerging from risk assessment controls), and a good testing / checking regime.
Concentrating on testing may well identify gaps, which can then be worked on. Some of the support material, (simple procedures / rules etc) could be produced by you if you have the skills, so that supervisors can then deliver. You can also 'monitor' standards as part of your role.
As has been pointed out, most elearning is (disappointingly) mainly page-turning powerpoint, with a database tagged on for record-keeping.
All can be done in less sophisticated, but possibly more tailored and effective ways.