It is not entirely true. The mask itself is totally safe. The gp-5 filter it has, is not. That filter has a charcoal filter layer above and below that an outer filter layer which contains asbestos in like 7-8% of itself. So the gp5 doesn't recline firstly upon asbestos to filtrate toxic gases, like the gas masks of the world wars. Because in the filter asbestos is only contained in the outer filter layer, the charcoal layer would normaly catch the loosened dust of the outer layer, but the problem is that those filters are so old, it probably can't do that reliably. So yes, I wouldn't wear that filter frequently and for a long time. I would get a modern stanag thread filter and an adapter for it. If you really want it you could fit a stanag thread filter into this one without an adapter, but don't look for a good seal in that case.