Depending on the nature or condition of these contaminants, the necessary leak-tightness can be provided by the impermeability of the protective integument and/or by any other appropriate means, such as ventilation and pressurisation systems designed to prevent the back-scattering of these contaminants.
Ag brath ar chineál nó ar bhail na n-ábhar salaithe sin, is féidir an teinne ligin ia gá a sholáthar trí neamh-tréscaoilteacht na forchlúide cosanta agus/nó trí aon mheán iomchuí eile, mar shampla córais aerála nó bhrúchóirithe atá ceaptha cúlscaipeadh na n-ábhar salaithe sin a chosc.