"Formaldehyde is toxic and potentially lethal in high doses. However, it is present in such small amounts in a flu vaccination that it is harmless."
So let me get this straight...they admit it's toxic and potentially lethal in high doses, but it's ALSO harmless at the same time....Sorry....common sense red flag is kicking in again.
You better recalibrate your 'common sense flag', because yes, thats exactly what they are saying and there's nothing paradoxical about that. Here are a few other things known to be toxic at high concentrations and safe at low levels:
iron, zinc, copper, vitamin-C, alcohol, caffeine, aspirin, salt, water
The dose is the poison, as they say.
There may be some substances for which there is possibly no 'safe' concentration. Formaldehyde is likely not one, because your body produces (and metabolizes) it all the time as part of it's normal physiological process. The amount of formaldehyde in a vaccine is far less than what's normally circulating in your blood. Formaldehyde is certainly linked to some serious health effects at sufficiently high doses but not at remotely close to the amount present in a vaccine.
If you are worried about it so much, maybe research what foods naturally contain formaldehyde, and compare to how much is in a vaccine.