•Acrylic acid is similarly corrosive as acetic acid to metals found in cultural heritage environments.•A headspace solid phase microextraction gas chromatography-mass spectrometry protocol showed ...that acrylic double-sided pressure sensitive adhesives (PSAs) with detectable amounts of acrylic acid or high levels of 2-ethylhexyl acrylate or acetic acid could be used to predict whether a PSA was inappropriate for use in cultural heritage environments.•Due to their VOC composition and artificial aging results, 3M™ 465, 3M™ 908 and Tesa® 88,250 PSAs were found to be most appropriate for use in cultural heritage environments.
An artificial aging protocol known as the Oddy test was combined with headspace solid phase micro-extraction (SPME) gas chromatography-mass spectrometry (GC–MS) data to identify which of 17 double-sided acrylic pressure-sensitive adhesives (PSAs) were safest to use in cultural heritage environments. Traditional Oddy testing showed every PSA corroded lead coupons while 1 also corroded copper and silver coupons. 10 PSAs were suitable for short-term use near cultural heritage artifacts while the remaining 7 were unsuitable. An adapted Oddy test identified whether several known acrylic-based adhesive precursor chemicals, including ethyl acrylate, n‑butyl acrylate, 2-ethylhexyl acrylate, acrylic acid, and abietic acid caused the observed corrosion. Lead coupons were extremely sensitive to acrylic acid, with a 5 × 10−5 mg L-1 Oddy test jar concentration capable of initiating corrosion at 60 °C and 50% RH. SPME GC–MS showed that any evidence of acrylic acid or acetic acid with peak areas larger than 19 million were both markers for unsuitable PSAs. 2-ethylhexyl acrylate was less reactive to metals though a GCMS peak area greater than 200 million was correlated with unsuitable PSAs. 3M™ 465, 3M™ 908, and Tesa® 88,250 tapes were concluded to be the best double-sided PSAs for use in cultural heritage environments.
•'3 in 1′ Oddy test was used to evaluate harmful materials for metallic cultural heritage.•Unlike the original Oddy test setup, metal coupons were hung from glass hooks.•Quantitative evaluation of ...Oddy test was performed as a complement to the visual rating.•Electrolytic cathodic reduction for silver and copper and mass gain for lead.•Quantitative methods allow selecting the safest material from those rated as suitable.
The Oddy test is a preventive conservation tool that helps to preserve real objects of cultural significance. To do this, it uses silver, copper and lead coupons as corrosion dosimeters. Despite its utility and extensive experience, one of its limitations is the lack of a quantitative assessment method to avoid the subjectivity of visual examination and numerically rank the tested materials into suitable (permanent or temporary) and unsuitable. To address these issues, we present a proof of concept for the incorporation of the methodology of the ISO 11844-2 standard into the assessment stage of the '3 in 1′ Oddy test. And so, use standardized quantification methods of corrosion rate for metal coupons such as electrochemical reduction for silver and copper coupons and gravimetric methods for lead coupon.
A traditional '3 in 1′ Oddy test has been performed to evaluate four materials known for their harmful nature to metallic cultural heritage: oak wood, medium density fibreboard (MDF), wool and leather. The electrochemical reduction method yields excellent results for copper and silver, allowing quantifying the corrosion even for the lightest tarnishing of the metal coupons that act as control or reference. For example, in the absence of contaminant-emitting material, the silver coupon lost 0.12 nm of thickness due to corrosion of the own conditions of the Oddy test (60 °C and 100%RH). Mass gain is also a convenient method with enough sensitivity to rank the corrosion of lead.
It has been shown that the ranking established by visual inspection alone can be misleading, rating similarly materials that produce large differences in corrosion rates. Moreover, in the case of copper, the visual rating of the tested materials does not agree with that obtained from electrochemical reduction. Further research is needed to establish the limits of this methodology, but results presented here demonstrate the feasibility and utility of this approach.
Nineteen brands of latex-free, powder-free, disposable nitrile glove were investigated for use when dry handling art. Results from a rub test, a modified Oddy test, scanning electron ...microscopy-energy dispersive spectroscopy (SEM-EDS), and ion chromatography (IC) were combined to identify gloves that caused the least damage to artificially aged metal coupons. The rub test involved repeated wiping of lead (Pb), copper (Cu), and silver (Ag) coupons with donned gloves then visually assessing the result to look for evidence of deposited residues. Ten brands deposited residues. The modified Oddy test studied the impact of glove handling on evidence of coupon corrosion. Twelve glove brands instigated moderate to severe corrosion of the coupons during artificial aging. SEM-EDS data showed that deposited residues led to pitting and corrosion of coupon surfaces with the presence of chlorine and oxygen dominating corrosion sites. Larger amounts of chloride ions (Cl
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) in gloves were affiliated generally with greater corrosion. Ansell Bioclean™ Biotac white cleanroom and Showa® 7500PF blue economy grade gloves deposited no visible residues, induced minimal corrosion, and showed lower anion contents relative to other gloves, making them the best brands tested here for dry handling art.
The sustainable, passive climatisation of display cases using saturated salt solutions is rarely applied nowadays. These solutions adjust the atmospheric humidity to the specific deliquescence ...relative humidity (DRH) of the salt. Practical problems like the risk of spilling or ‘creeping’ of salts can be overcome. The DRH of suitable salts does not depend significantly on temperature. Solutions were Oddy-tested to check for corrosive emissions of the acids corresponding to the salt anions. Only magnesium chloride failed in accordance with thermodynamic calculations of the HCl vapour pressure. Solutions can absorb water-soluble pollutants like acids or aldehydes from the atmosphere, as has successfully been demonstrated for formaldehyde in chamber experiments. The alkaline potassium carbonate solution not only dissolves acids and aldehydes but also reacts with them chemically. Research needs to further study the absorption of pollutants are outlined. A revival of the saturated salt solution would make museum displays more sustainable.
Rigid, unplasticized poly(vinyl chloride) (PVC-U) sheet products were evaluated comprehensively for the first time with regard to their use in museum showcase construction. The compositions of ...numerous name brand products (Sintra, Forex, Komatex, Komacel, Celtec, Ex-cel FF, PALIGHT, and ePVC) have been determined using pyrolysis-gas chromatography-mass spectrometry, while their volatile emissions were assessed using modified Oddy tests as well as direct thermal desorption chromatography at elevated temperatures. Despite frequently passing the aggressive conditions of the Oddy test, most premium quality brands were found to release 2-ethylhexyl thioglycolate (2-EHTG), a sulfur-bearing byproduct of a heat stabilizing additive. Importantly, only the economy versions of PVC-U analyzed in this study (Komacel and ePVC) did not contain the sulfur compound. This volatile thioglycolate was shown here using molecular spectroscopies to deposit on and react with copper and silver surfaces. Similarly, lead white pigmented watercolor was blackened by the thioglycolate. Based on these results, alternative materials are recommended for display cases that will contain sulfide-sensitive materials like metals.
Since the introduction of the Oddy test in 1973, many museums and cultural institutions have put the method in use, developing their own versions and protocols. Currently the 3-in-1 version, ...temperature at 60 ºC and 2 g of tested material are set as common practice; however, other variables of the test are not standardized. The purpose of this study is to examine current versions of the Oddy test, to identify differences in the results derived from variations in the procedures, and ultimately raising awareness within the conservation community to work together towards a standardized protocol. In this article, we review the available information on the methodological differences in Oddy test protocols published in the literature related to glassware cleaning, coupon preparation, reaction vessel setup and rating of materials. Based on the review, and to highlight the many variables that could affect the results of the test, seven European cultural institutions working under the H2020 IPERION HS project performed a comparative 3-in-1 Oddy test by blindly evaluating the same ten materials. Each institution used its own test methodology but some guidelines were advised: (1) Detergents as a cleaning procedure for glassware, (2) P600 sandpaper or micromesh pad close to 1500 to prepare metal coupons and (3) 1:100 as water–air ratio. Despite this, differences between institutions’ results were still observed. Some of them are due to the differences in the coupons preparation, either in the sanding pattern or in the edge area. In order to separate the contribution of the experimental setup and the subjectivity of the evaluation in the discrepancies, coupons from all institutions have been rated by a single team of judges with experience in the Oddy Test. Results show that differences in the evaluation criteria play a relevant role in the discrepancies of the results, especially for institutions with less experience in the test. These results highlight the need to further standardize the methodology and criteria for visual assessment. Nevertheless, the Oddy test has been found to be reliable for the identification of materials that produce emissions hazardous for the conservation of cultural assets.
Cultural property and art objects often contain metallic or ceramic materials that can react corrosively with compounds like formic and acetic acid from the ambient air. For this reason, only ...materials that cannot damage the cultural property by gaseous escaping substances are used for the construction of museum showcases. Due to its chemical composition, wood is excluded as a construction material in museums.
In this study, three wood species, beech (Fagus sylvatica L), alder (Alnus), and walnut (Juglans regia), were treated with different concentrations of NaOH solutions to limit their corrosion potential to the extent that the treated wood could be used for the construction of museum display cases. The Oddy accelerated corrosion test, which has established itself as a proven test method for determining the suitability of materials in museums, offers a test method for measuring the corrosion potential of materials. The results show that all three types of wood pass the Oddy test by treatment with a 3% NaOH solution, whereas all untreated samples had to be classified as unsuitable for use in museums, as expected, according to the underlying evaluation scheme.
The 'Oddy test' is an accelerated corrosion test introduced in the 1970s at the British Museum to identify materials likely to emit volatile substances that could harm museum artefacts. It is carried ...out in many museums all around the world, but not always using the same methodology, which makes it difficult to compare and share test results between institutions. Refinements to the Oddy test methodology have been implemented at the British Museum over the last decade and the aim of this paper is to present these and promote consistency across institutions. The modifications introduced concern the method used to wash the glassware, the preparation of the metal coupons, and standard methods for preparing samples of liquid coatings, adhesives, and adhesive tapes. Finally, conducting Oddy tests is time consuming and measures employed at the British Museum to reduce the number of materials to be tested and streamline testing are described.
Cellulose ethers, like methyl cellulose (MC) or hydroxypropyl cellulose (HPC), are widely used in conservation. They also occur as additives and rheology modifiers in various products like ...dispersions or gels. Do such products release harmful volatile organic compounds (VOC) during their accelerated aging? A mass testing series utilizing the Oddy test of 60 commercial cellulose ethers ranks the products in safe for permanent use (P, no corrosion), only for temporary use (T, slight corrosion), and unsuitable at all (F, heavy corrosion). Results show that 55% of the products passed the test whereas 33% are for temporary use as slight corrosion occurred on at least one metal coupon and only 11% failed the Oddy test. Raman measurements of the corrosion products identified oxides like massicot, litharge, cuprite, and tenorite among carbonates (hydrocerussite, plumbonacrite), and acetates like basic lead acetate, lead acetate trihydrate as well as lead formate as main phases. For example, commercial, industrial Klucel® G (HPC) scored a T rating through slight corrosion on the lead coupon. Basic lead acetate among other phases indicates the presence of acetic acid. Additional measurements of the sample with thermal desorption GC–MS utilizing the BEMMA scheme confirm the high acetic acid outgassing and reveal the presence of a small amount of formaldehyde.
