Worksheet featuring twelve yellow triangular warning signs used in laboratories to indicate hazards such as explosions, radiation, and electric shocks.

The task is to identify the lab safety signs shown in the image. Below is the explanation and identification of each sign:

Row 1:

1. Explosion Hazard Sign
- Symbol: Triangle with an explosion and flying debris.
- Meaning: Indicates the presence of explosive materials or a risk of explosion.

2. Flammable Materials Sign
- Symbol: Triangle with a flame.
- Meaning: Warns of flammable substances that can catch fire easily.

3. Radiation Hazard Sign
- Symbol: Triangle with three radiating arcs.
- Meaning: Indicates the presence of radioactive materials or radiation hazards.

4. Combustible Liquids Sign
- Symbol: Triangle with a flame over a circle.
- Meaning: Warns of liquids that can ignite and burn, posing a fire hazard.

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Row 2:

5. Slippery Surface Sign
- Symbol: Triangle with a person slipping.
- Meaning: Indicates a slippery surface that could cause falls.

6. Ionizing Radiation Sign
- Symbol: Triangle with a stylized atom or radiation symbol.
- Meaning: Warns of ionizing radiation, such as X-rays or gamma rays.

7. Fall Hazard Sign
- Symbol: Triangle with a person falling.
- Meaning: Indicates a risk of falling from heights or uneven surfaces.

8. Vibration Hazard Sign
- Symbol: Triangle with wavy lines.
- Meaning: Warns of exposure to vibrations, which can be harmful to health.

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Row 3:

9. Prohibited Actions Sign
- Symbol: Triangle with a crossed-out circle.
- Meaning: Indicates actions that are prohibited in the area.

10. Toxic Substances Sign
- Symbol: Triangle with a dead tree and skull.
- Meaning: Warns of toxic or hazardous substances that can harm health.

11. Rotating Machinery Sign
- Symbol: Triangle with a gear.
- Meaning: Indicates the presence of rotating machinery that could pose a danger.

12. Fragile Materials Sign
- Symbol: Triangle with a broken container.
- Meaning: Warns of fragile items that should be handled with care to avoid breakage.

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Final Answer:

Here is the list of identified signs:
1. Explosion Hazard
2. Flammable Materials
3. Radiation Hazard
4. Combustible Liquids
5. Slippery Surface
6. Ionizing Radiation
7. Fall Hazard
8. Vibration Hazard
9. Prohibited Actions
10. Toxic Substances
11. Rotating Machinery
12. Fragile Materials

Boxed Final Answer:
\boxed{
\begin{array}{cccc}
\text{Explosion Hazard} & \text{Flammable Materials} & \text{Radiation Hazard} & \text{Combustible Liquids} \\
\text{Slippery Surface} & \text{Ionizing Radiation} & \text{Fall Hazard} & \text{Vibration Hazard} \\
\text{Prohibited Actions} & \text{Toxic Substances} & \text{Rotating Machinery} & \text{Fragile Materials} \\
\end{array}
}