As is the case with any wet lab experiment, safety plays a major role. Our experiments can be categorized into three major areas in terms of safety:

1) Lab Environment Safety

2) Experiment Process Safety

3) Final Product Safety

• Lab safety training at the start of wet lab training

Proper Personal: long pants, no slippers, lab coats, and gloves whenever in the lab. Wash your hands before and after every experiment, and no food or drinks in the lab area. Rinse every instrument with ddH₂O before use, sterilize hands and tools with 75% alcohol before entering the clean bench.

• Chemical Safety

Identification and Awareness: All chemical containers must bear clear labels indicating the chemical name, concentration, hazardous properties, and preparation date. It is imperative to read and understand the Material Safety Data Sheet (MSDS/SDS).

Safe Storage: Store by Category, strictly prohibit mixing incompatible chemicals (e.g., acids and bases, oxidizers and reducing agents). Flammable substances must be stored in explosion-proof cabinets; highly corrosive chemicals in corrosion-resistant trays; toxic substances under lock and key. Maintain ventilation and ensure containers are tightly sealed.

Safe Use: Wear appropriate personal protective equipment (PPE), such as chemical-resistant gloves, safety goggles, and lab coats. Operate volatile, toxic, or irritant chemicals within a fume hood. Be familiar with emergency procedures, including responses to chemical spills, leaks, and fires.

• Bacteria Experiments: Sterilize hands with 75% alcohol. All the experiments dealing with cells for our project deal with E. coli cells. If we had to transfer solutions, grow them on agar plates, etc., we would all perform these steps inside the clean bench. This prevents the cells from being exposed to less sterile environments, but also allows for regulated disposal and operation of all our cell experiments.
• Chromium Experiments: Wear PPE, extra gloves, masks, and goggles. Chromium is a carcinogen. Though our concentrations (the highest being 100mg/L) are diluted, extra coverage is mandatory for every experiment to prevent unintended contact with the skin. Chromium is obtainable in lab settings through official requests, but chromium-containing wastewater is strictly not accessible for non-filtration usages within China.
• Toxic Chemical Experiments: Wear PPE, extra gloves, and masks. Chemicals like gelred, SDS, as well as some other buffers used in our experiments, are toxic. Hence, for these experiments, we were required to wear extra gloves and masks.
• High Temperature Experiments: Check the machinery before use: Microwave, PCR machine, Water Bath Pot.
• Centrifuge: Must balance evenly and close the lid.
• Waste Disposal: All our experiment waste goes into specified biohazard trash bags (which are professionally processed). We disposed of all chromium-containing waste into a specified biohazard trash bag.
• Chromium Regulations in drinking water: China: 0.5 mg/L (<1.5mg/L in industrial wastewater); USA: 0.1 mg/L; Europe: 0.05 mg/L.

• Make sure the bacteria are killed after purification.
• Filtration layers to modify wastewater.
• Heavy emphasis on when and how it is used.

1. China Water Risk WATER UNIVERSE Maximum Allowable Discharge Concentrations for Heavy Metals in China.
2. US EPA. “Chromium in Drinking Water | US EPA.” US EPA, 22 Sept. 2015, www.epa.gov/sdwa/chromium-drinking-water.
3. Vaiopoulou, Eleni, and Petros Gikas. “Regulations for Chromium Emissions to the Aquatic Environment in Europe and Elsewhere.” Chemosphere, vol. 254, Sept. 2020, p. 126876, https://doi.org/10.1016/j.chemosphere.2020.126876.