Nebuliser Masks

This may seem I bit of a silly question. Does anyone know of a good way to get rid of the very plastic chemimical new equipment smell you get with nebuliser masks. I keep washing the masks as directed but the new equipment smell does not want to go away and it is beginning to get on my nerves...

[yaf_user681_30355]

I don't have this problem as I use the mouth piece but I would try soaking it for a few hours in soapy water (very small amount of fragrant washing up liquid.)