Err, back on track - I honestly do NOT like the sound of GREEN scabs, V. Sounds quite iffy to me, frankly.
I think I know what V means having had some quite deep burns on my tummy one time due to falling asleep with a hot water bottle clutched to it (the burns rather than being because the hot bottle was scalding, were likely just from a heat build up). I think so long as it's not red and raised round the edges they should be OK, but frankly a pharmacist should be able to tell you V if you just popped into Boots or somewhere.
The whole subject of employment practices is scandalous these days. I am fortunate that when I was an employee I always worked for employers that were honest and above board and moreover simple! I did do a while with a temp agency, but built into the hourly pay was an amount for holiday and sick pay.