The use of lead in ISO 11844 for determining indoor air corrosivity

Beskrivelse

Lead has been included in ISO 11844 since 2020, as a standard test with high sensitivity to gaseous organic acids. However, means of classifying corrosivity with lead are only given by mass loss determination (by acid pickling) of the metal coupons, and not by the easier method of weight measurement (mass increase) as for the other metals included in the standard. Furthermore, the non-linear corrosion rate of lead makes it difficult to compare different measurements if they are not exposed for exactly the same amount of time, which is specified in the standard as one year. In my presentation I will present several examples of lead coupon exposures in museum environments for various periods of time (some for several years), as well as examples of laboratory exposures of lead coupons to elevated levels of organic acids, relative humidity, hydrogen sulphide; either as single factors or in combinations. The observed corrosion rates will be compared against simultaneous measurements of climate and pollutant levels, and corrosion measurements by other means (by AirCorr loggers with lead sensors). I will in the presentation argue that determination of indoor corrosivity can be done by mass increase measurements also for lead, as the method is sufficiently accurate, is easy, and the same coupons can be reused and their corrosion rate development monitored over time. Levels of mass increase of lead for the classification of indoor atmosphere corrosivity will be proposed.

Periode	19 nov. 2024
Begivenhedstitel	International Conference on Indoor Air Quality in Heritage and Historic Environments
Begivenhedstype	Konference
Konferencenummer	16
Placering	New York City, USAVis på kort
Grad af anerkendelse	International