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Exposure of artists' colorants to airborne formaldehyde

1992; Taylor & Francis; Volume: 37; Issue: 3 Linguagem: Inglês

10.1179/sic.1992.37.3.201

2047-0584

Edwin L. Williams, Éric Grosjean, Daniel Grosjean,

Building materials and conservation

Thirty artists' colors have been exposed for 12weeks to 120ppb of formaldehyde in purified air as well as to purified air alone (control experiment). The exposure was carried out in the dark at ambient temperature (19 ± 2°C) and humidity (RH 44–52%). Color change (∆E) was measured using a reflectance color analyzer after one, two, three, four, six, eight, 11 and 12 weeks of exposure. Color parameters (x, y, X, Y, Z, L*, a*, b* and ∆E)"were also calculated from the 380–700nm spectra, recorded with a reflectance spectrophotometer, of unexposed colorants and of colorants exposed for 12 weeks to purified air and to formaldehyde. Regression analysis of the two data sets indicated that the color changes measured by these two methods were in excellent agreement (nearunity slopes, with correlation coefficients > 0.99). Exposure to either formaldehyde or pure air on watercolor paper resulted in little or no color change for all the colorants tested, including inorganic colorants, alizarin lakes, quinacridones, triphenyl methanes, indigo derivatives, arylamides and natural colorants such as curcumin. Formaldehyde, which is ubiquitous in indoor air, including museum air, does not appear to be a major threat to colorants in museum collections.