Chemical Toxicity Database
It’s important to understand the toxicity of the chemicals that you use.
EU Database
US EPA Chemical Substances Inventory
IC2 Chemical Hazard Assessment Database
Greener Chemicals
Solvent Substitution
There are a number excellent solvent guides:
Beyond Benign Greener Solvent Guide
Unified version of general solvent selection guides for medicinal chemists
Pfizer solvent replacement table
| Solvent | Issues | Alternatives |
|---|---|---|
| Pentane | Lower flash point than other similar solvents | Heptane |
| Diethyl ether | Lower flash point than other similar solvents | 2-MeTHF, TBME |
| Diisopropyl ether | Powerful peroxide formation compared to similar solvents | 2-MeTHF, TBME |
| Hexane(s) | More toxic than other similar solvents | Heptane |
| Benzene | Carcinogen | Toluene |
| Chloroform | Carcinogen | DCM |
| 1,2-DCE | Carcinogen | DCM |
| 1,2-DME | Carcinogen | 2-MeTHF, TBME |
| Pyridine | Carcinogenicity (not classifiable) | Triethylamine (base) |
| 1,4-Dioxane | Carcinogenicity (not classifiable) | 2-MeTHF, TBME |
| DCM | Emissions | Application dependant |
| Carbon tetrachloride | Emissions | DCM |
| DMF | Reproductive toxicity | Acetonitrile |
| DMAc | Reproductive toxicity | Acetonitrile |
| NMP | Reproductive toxicity | Acetonitrile |
Chemical Substitutions
Catsub: Catsub provides 300 examples of substituting hazardous chemicals with safer alternatives.
Cefic LRI Toolbox: The Cefic LRI Toolbox focuses on risk assessment and toxicity testing for chemical substitutions.
EC (2012) Guidance: The EC Guidance provides a framework to identify chemicals that should be substituted and evaluates alternatives based on risk, technical requirements, practicality, and cost.
EPA - Design for the Environment Alternatives Assessments: The EPA’s Design for the Environment program offers assessments of alternative chemicals to promote environmentally friendly choices.
German Column Model (Spaltenmodell): The German Column Model compares the hazards and risks of different chemicals to aid in decision-making for substitution.
Green Alternatives Wizard: The Green Alternatives Wizard suggests potential substitutes for hazardous chemicals.
INRS: INRS helps identify potential areas of exposure in the workplace and compares chemicals to facilitate substitution.
Keki-Arvi: Keki-Arvi specializes in risk assessment and avoidance for chemical substitutions.
OECD Toolbox: The OECD Toolbox provides alternatives assessment and general regulation resources, including lists and methodologies.
Stoffenmanager: Stoffenmanager offers chemical exposure assessment and possible control measures, emphasizing substitution.
SUBSPORT: SUBSPORT provides information on alternative substances and technologies for chemical substitution.
Other
As discussed in the Fumehoods section, using more Green Chemistry and using fewer harmful solvents and reactions means that the air change rate in the fume hood and lab can be reduced.
Exchange all mercury thermometers for safer alternatives
Chemical Recycling
By implementing solvent recycling practices, the usage of organic solvents can be reduced, resulting in decreased exposure and chemical waste. Various solvents such as acetone, acetonitrile, xylene, alcohol, and formalin can be efficiently distilled back to a purity level of over 99% using on-site recyclers or services provided by vendors. This approach promotes sustainability by reusing solvents and minimizing the need for new solvent production.
Save Cleaning Acetone
Acetone is one of the most common solvent used to clean glassware, especially for products insoluable in water. Assuming it’s safe, save your acetone after use and reuse it. Washing acetone doesn’t need to be pure or dry. Have a few containers of varying contamination - say, pure, one-pass, two-pass, three pass.
You first wash your dirty flask with the three-pass acetone (that has already been used three times) and dispose. Then use the two-pass acetone (that has already been used twice) and re-label as “three-pass”. Then use the one pass acetone (which has previously been used once) to rise and re-label as “two-pass”. Lastly rinse with fresh acetone and label that as “one-pass”. Repeat for all the flasks you have to use that day or week.
Instead of putting your used solvent into the waste, you can also use a rotary-evaporator to recover some of your washing solvents. Pour your acetone waste into a round bottom flask and put it on your rotovap and remove the solvent as normal (obviously not until dry). As usual, you should add a cold trap to avoid the vacuum pump from pullig the solvent vapour past the condenser into the pump (you can also insert in-line needle valve between vacuum pump and rotovap to give better vacuum control). Pour the collected acetone from collection flask and cold trap back into wash bottle for cleaning. This can be used for any solvents with low boiling point - e.g. methanol, acetonitrile and ethyl acetate.
Other
Xylene, alcohol, and formalin may be recycled by the use of a CBG Biotech Supreme Solvent Recycler (Thermo-Fisher Scientific)
Disposal
To ensure the safe disposal of chemical waste, it is essential to treat the waste as close to its source as feasible. This approach minimizes the risks associated with transportation and handling of hazardous materials. By implementing proper waste treatment measures at or near the site of generation, potential environmental and safety hazards can be mitigated effectively.
Detoxifying Acetonitrile
Even though acetonitrile has been labeled as a “recommended” solvent by the solvent guides above, it has been shown to be a known teratogen and a skin and eye irritant.
Acetonitrile most often used in chromatography as a mobile phase. Try adding NaOH to detoxify acetonitrile enough to pour down the sink.
Procedure: Dilute to 10 vol% CH3CN/water. For every liter of 10 vol% CH3CN, add 475 mL of 10 M NaOH. Leave the solution at 20 °C for 25 days in a hood or heat to 80 °C for 70 min. To reduce the CH3CN concentration to 0.0025 vol%. Mix with waste acid to neutralize.
CH3CN + NaOH + H2O → CH3CO2Na + NH3
Source: Gilomen et al.Gilomen1995_Article_DetoxificationOfAcetonitrileWa.pdf (302.4 KB)
Careful: Unfortunately, rarely is the aceonitrile pure after HPLC use, so be aware of what other chemicals are in your solvent.
More ways to detoxify waste: Garrigues et al.1-s2.0-S0165993610001123-main.pdf (317.9 KB)
Solvent End-of-Life Options
(Dr Lindsey Soh from Lafayette College)
Sustainability Comparison
(Dr Lindsey Soh from Lafayette College)
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