Final answer:
Excessive sunlight exposure is not considered an environmental hazard when operating a forklift, unlike poor ventilation, noise pollution, and slippery floors.
Step-by-step explanation:
The option that is not an environmental hazard when operating a forklift is d) Excessive sunlight exposure. While operating a forklift, poor ventilation can lead to the accumulation of exhaust fumes or other hazardous gases, noise pollution can be caused by the forklift's operations leading to hearing damage, and slippery floors can significantly increase the risk of accidents. Excessive sunlight exposure, although an environmental consideration, is not typically classified as a hazard in the context of forklift operation, as it does not directly impact the mechanical operation or safety concerns associated with the immediate environment where the forklift is being used.