Avoiding common risks in school greenhouses

Key takeaways:

• School greenhouses have the potential to become dangerously hot and humid. That’s why they should have a Wet Bulb Globe Temperature meter.
• If students and staff are harvesting food in the greenhouse, they need to inspect it before storage to check for signs of pests or damage.
• All tools should be immediately placed back in their container once students and staff are done with them.

Greenhouses are a tremendous resource for teaching students in school  vocational agriculture programs. However, they also present liability issues if a student or staff member becomes injured or ill.

Schools that have greenhouses or garden-like facilities should establish standard protocol for minimizing risk. CM Regent’s risk control specialists offer the following tips for different categories of risk:

Pest management

Pests thrive in garden environments, and if they can gain access to a warm greenhouse in the middle of winter, they will. To prevent this, schools should eliminate points of entry by:

• Keeping windows and doors closed when areas are unoccupied.
• Sealing gaps and openings around windows and doors.
• Sealing cracks and holes in exterior walls and around pipes and electrical equipment.
• Do not use pesticides or other pest killers due to food safety and allergies outlined below.

Food safety

Greenhouses produce food that must be kept safe — especially if a school intends for students and staff to eventually eat the food. Staff members should:

• Make sure they and their students are healthy when harvesting the food.
• Use food grade sanitizing procedures.
• Store food in clean, food-grade containers after it has been harvested.
• Inspect produce, and do not harvest anything that has been gnawed, damaged or has animal feces on it.

Chemical safety

Gardening and plant maintenance sometimes requires the use of chemicals, which can cause mild to severe skin irritation. To prevent this, students and staff should:

• Wear personal protective equipment (PPE) such as gloves, long-sleeved shirts, long pants and closed-toed shoes.
• Wash their hands immediately after working in the greenhouse.
• Dispose of all chemicals properly and according to their manufacturer’s instructions.

Wet Bulb Globe Temperature measurement

A Wet Bulb Globe Temperature (WBGT) is a measurement of several parameters taken in direct sunlight, including the current temperature, wind speed, sun angle, relative humidity and cloud cover. It is therefore a more accurate measure of heat than the heat index. In fact, WGBT often shows higher values inside a greenhouse than outside, because of trapped heat.

It is important that schools with greenhouses maintain a WBGT meter to protect students and staff. Otherwise, they are at risk for several different types of heat illnesses—particularly as the weather gets warmer outside.

Staff members should consider scheduling greenhouse time early in the morning or in the evening to avoid high WBGT measurements.

Bloodborne pathogen safety

Not only are greenhouses full of sharp tools for tending plants, but a number of plants can also draw blood if not handled carefully. This increases the risk of students and staff members being exposed to bloodborne pathogens (BBPs).

To reduce this risk, schools should:

• Require anyone working in the greenhouse to wear PPE at all times. It is especially important that they wear gloves to avoid injury while handling plants.
• Similarly, anyone who is providing first aid assistance in the greenhouse needs to wear protective gloves.
• Establish a reporting procedure for any incident that may involve bodily fluids.

Tool and equipment safety

As noted above, there are many sharp tools stored in a greenhouse that could potentially injure a student or staff member. To avoid injury, schools should:

• Always store shovels, trowels and rakes in a designated area with blades and handles securely fastened.
• Store hand tools in use upright against a stable surface, so they do not fall and create a trip/slip hazard.
• Keep pathways clear of hoses, rocks and debris. Use good housekeeping practices to ensure any uneven spots or holes are filled promptly.

Avoiding allergic reactions

Some students or staff members may have an adverse response to a specific type of plant. (For example, certain lilies can trigger an allergic reaction.) Students should have unrestricted access to their EpiPens, and staff members should be trained on how to use them.

A greenhouse poses both unique opportunities and unique risks. Schools need to take the time to address each of these risks.

Click for more risk management information on vocational agriculture programs.

How to keep students and staff safe in greenhouses

Q: How can schools prevent pests in greenhouses?
A: By keeping doors/windows closed and sealing gaps or cracks where pests could enter.

Q: What ensures food safety when harvesting produce?
A: Only harvest when healthy, use clean containers and avoid damaged or contaminated produce.

Q: Why is WBGT monitoring important?
A: Greenhouses trap heat, so checking WBGT helps prevent heat-related illnesses.

Q: How can injuries and exposure to hazards be reduced?
A: Use PPE, store tools safely, keep walkways clear, handle chemicals properly and report any blood-related incidents.