Not all heroes wear lab coats

​Introduction

For the past 10 weeks, I've been carrying out research for Sustainability in Conservation's (SIC) Greener Solvents Project, both remotely and on site in Winterthur's conservation department. I've been researching with Gwendoline Fife from the Greener Solvents Project and Rosie Grayburn from Winterthur, funded by the UD Summer Scholars Program​. When I first started the project, I pictured myself in a lab coat and goggles, single-handedly saving the Earth with my mighty chemistry powers. I thought I was going to be testing alternative solvents that are healthier for the environment and our own health and safety.

Allow me to show you how reality measured up to my own expectations in this Reality Check:

Number of Greener solvents tested practically: 0

Times I wore a lab coat and goggles: 2

Solvents I used: acetone (that's it)

Months waiting for chemicals to arrive: 3

Mighty chemistry powers: still waiting on them to kick in.

Amazing databases created for this project: 1

Solvents in said database: 65 and counting!

Rooms with organized chemicals and updated inventories: 4 (this number is much more impressive in person)

Emails sent: a lot​

Instead of testing greener solvents this summer, I created a database that contains information about commonly used solvents in the conservation field. The database is divided into four major categories: identification, solvent properties, health and safety, and information about how the solvent is used in conservation. Its main purpose is to allow conservators to see potential “greener" solvent alternatives to the ones already in their cabinets based on their particular substrate and their environmental impact.

The term “greener solvent" pertains to solvents that are less hazardous to use and more friendly to the environment in terms of their disposal and creation. Most of my foundation about greener solvents comes from SIC's Greener Solvents in Conservation Handbook, ed Gwendoline R. Fife, Archetype publications, 2021. This handbook serves as an introduction to solvents in conservation as well as a guide to replacing the most harmful chemicals with greener solvents in labs. As the handbook shares how to assess chemical inventories to consider alternative greener solvents, the database will act as a supplementary reference regarding the solvent's use practically. This means that the handbook helps a conservator identify their rather nasty solvents and the ways to replace them. Then, the database will provide an alternative solvent that might work effectively in the same substrate. With this idea in mind, I got to work creating a database that can provide these greener alternatives.

​The Database

The database, created with Google Sheets, has TWENTY FOUR columns of headings. As this would be very overwhelming to try to take in all at once, this section will be split into the four categories that divide the database. Each row is a different solvent, while each column is a different piece of information about the solvent. ​Here’s the Google doc if you want to take a look at the project as it’s meant to be viewed​.

​Identification Section

This is the leftmost section of the database.

It shows the substrate, solvent name, CAS number, and the chemical formula. This section is pretty straightforward, relatively speaking. The substrate list is defined by SIC's Greener Solvents Project according to ICOM-CC's working groups, and includes bone, glass, ceramic, leather, metals, paint, paper, plastics, textiles, and wood. Solvents pose different risks to different substrates, so it's important to note which substrate the solvent can be used on.

​Safety Section

This is the section second to the left, in between Identification and Data.

This is the section with the most subheadings. First is the occupational exposure area, which has Threshold Limit Values with Time Weighted Averages (TLV - TWA for short) as well as Short Term Exposure Limits (STEL) in both ppm and in mg/m3. Using safety data sheets (SDS) for each solvent, most listed several TLV and STEL values from three different agencies: the National Institute for Occupational Safety and Health​ (NiOSH), Occupational Safety and Health Association (OSHA), and the American Conference of Governmental Hygienists (ACGIH). I chose to include the most conservative value to put in this section, and used colors to signal which agency the data is from. Most sds sheets also included the solvent's status as a carcinogen using the ACGIH's system. For Hazards, I used the GHS pictograms. ​

The Chem 21 section is from the CHEM 21 Selection Guide of Classical and Less Classical Solvents​, a table recommended from The Greener Solvent Handbook. The table provides a list of 50 or so solvents, each complete with a safety, health, and environmental score as well as the related overall recommendation rating for each solvent. ​

​Data Section

This is the section third to the left, in between Safety and Information.

Boiling Point, Relative Evaporation Rates, and Hansen Solubility Parameters​ (HSP) are discussed in this section. This data can be used to compare solvents, and are also helpful in determining how solvents can mix with other solvents to make solutions. For Relative Evaporation Rates, I chose to compare it to Butyl Acetate, as most of the data I looked at used butyl acetate as a basis. A lot of the SDS sheets I looked at did not include evaporation rates, so some of this section is blank.

​Information Section

This is the rightmost section.

This section has the least amount of information filled in, due to the fact that I could not test greener alternatives this summer. However, this section has the space for others to fill in greener solvent alternatives as well as the practicality of the alternative. If a greener solvent has to be kept at very low temperatures, or needs a certain instrument in order to work, then that kind of information would go into the Practicality of Alternative column. ​

This also has a place for references. I have been mostly storing SDS sheets in there, but for a small number of solvents, I have a paper linked about potential greener alternatives. ​

​Something I Learned!

One of my major takeaways from this project is the importance of accessibility of information. The original plan for this project included me testing solvent alternatives provided by a chemical company based on the similarities of their solvent data. As we are still waiting for them to approve our request, I learned that not all information is readily accessible.

While researching the database, much of the solvent information I needed was qualitative; I found these numbers in tables, in SDS sheets, and in textbooks. This is the work I conducted remotely. Not all of this data was easy to find (see: Emails sent in my Reality check) but it at least exists in print or online somewhere. All of the people I emailed were eager to help me out and provide data. But this data was scattered across the internet. Should this data about solvent properties be so hard to find?

What was frustrating was there was more information I needed to fill out the database, but it wasn't something I could look up. This information was the knowledge that comes from experience, particularly hands-on. How could I know which solvents paintings conservators use versus paper when I have never conserved a painting or a paper object? Having only two years of college under my belt (and all of it during COVID), there is so much that I don't know yet about chemicals in conservation. It's okay that I don't know this information, but I wish I could have filled out my database completely.

As I worked in person, at Winterthur helping to complete chemical inventories and archiving chemical samples, I learned ways that Winterthur organizes and shares their information in databases. I saw how employees could access information and by the same token, choose NOT to consult or update their databases. A database can hold useful information, but if people won't use it, then there is no point in making one. These experiences of updating older, outdated databases taught me that it is imperative to consider how people will use a database, not only the information that it contains.

The more I learned about workplace safety for this project, the more I wish I learned about in school. One of my professors told me once that one of her painting conservator roommates lost her sense of smell while working with chemicals. While this comedically made her a bad roommate because she could not smell odors in their shared household, the thought that my career could impact my health and it being potentially accepted as part of the job is terrifying. 

What Comes Next?

The next step is for someone to fill in the parts of the database that I couldn't. Primarily, that would be the substrate column and the information section. This section contains relevant information about how conservators use the solvent and what greener solvents could potentially replace it. I think there is potential to add or edit the information columns, since I have not filled them out substantially. I fully expect this database to grow and evolve as information is added. To fill in the greener solvent column, someone would need to test the potential alternatives to see if they would even work in particular substrates. Additionally, there are probably hundreds of solvents out there that can be added into the database. The Greener Solvent project aims to find and test these solvents as their primary goal. 

Continuing this research will introduce solvent alternatives into conservation labs, an area where there is generally little information available. The more information that the database contains, the more information that conservators can use to create healthier labs. Across the art and heritage conservation field, conservators use a wide range of solvents on a similarly varied range of materials, which allows for many different combinations of solvents and substrates. The database will serve as a reference for how each solvent can be used in each substrate, and specifically what greener alternative could replace the solvent in that instance. Conservators should have access to resources that they can use to make their labs safer for themselves and the environment. 

About The Intern

Lisa Clifford is a junior Art Conservation major completing her undergraduate degree at the University of Delaware. She has an interest in databases and generally making the field of art conservation a more organized place. Any questions about her work, contact her at liscliff@udel.edu!