Phosphorus (P) is a crucial macronutrient to plant development and agricultural production. However, rock phosphate reserves are finite and estimated to be depleted in coming years. Recycling phosphorus through high phosphorus-containing waste may be a possible substitute to food production enabling phosphorus use. Exhausted fire extinguisher powder (EEP) is primarily composed of monoammonium phosphate and may be a secondary phosphorus source. This article highlights the potential for EEP to be used in agriculture considering chemical composition, any safety concerns and the practical management of EEP waste. The heavy metals are below concentration thresholds, indicating the EEP is safe to apply onto land. However, the rapid volatility, dust emissions and low solubility of EEP are all challenges to applying EEP waste to agricultural fields without some form of pretreatment. Applying EEP with composting or densification is one way to mitigate the issues associated with using EEP waste while reclaiming nutrients, as well as, addressing soil and environmental health. Therefore, utilizing EEP as a fertilizer may be considered a sustainable practice to conserve phosphorus and to reinforce closed loop nutrient economy in agriculture.