A transport refrigeration system, comprising: a primary controller; a refrigerated container with a plurality of compartments; and a hazard detection system comprising: an auxiliary controller; a plurality of sensors respectively distributed in the plurality of compartments of the refrigerated container of the transport refrigeration system, each of the plurality of sensors operationally connected to and controlled by the auxiliary controller; and a plurality of fans operationally connected to the plurality of sensors and configured to draw air toward the plurality of sensors, and wherein the plurality of sensors detect refrigerant, wherein: the auxiliary controller is operatively connected to the primary controller; the auxiliary controller is configured to transmit a first communication, to the primary controller of the transport refrigeration system, indicative of determining at the auxiliary controller that a hazard condition is detected; the primary controller is configured to output a response including communicating an alert and/or engaging in a safety procedure when the primary controller receives the first communication; and the primary controller is configured to engaging the safety procedure by drawing air out of the plurality of compartments with the plurality of fans when the primary controller receives the first communication. a primary controller; a refrigerated container with a plurality of compartments; and a hazard detection system comprising: an auxiliary controller; a plurality of sensors respectively distributed in the plurality of compartments of the refrigerated container of the transport refrigeration system, each of the plurality of sensors operationally connected to and controlled by the auxiliary controller; and a plurality of fans operationally connected to the plurality of sensors and configured to draw air toward the plurality of sensors, and wherein the plurality of sensors detect refrigerant, wherein: the auxiliary controller is operatively connected to the primary controller; the auxiliary controller is configured to transmit a first communication, to the primary controller of the transport refrigeration system, indicative of determining at the auxiliary controller that a hazard condition is detected; the primary controller is configured to output a response including communicating an alert and/or engaging in a safety procedure when the primary controller receives the first communication; and the primary controller is configured to engaging the safety procedure by drawing air out of the plurality of compartments with the plurality of fans when the primary controller receives the first communication. an auxiliary controller; a plurality of sensors respectively distributed in the plurality of compartments of the refrigerated container of the transport refrigeration system, each of the plurality of sensors operationally connected to and controlled by the auxiliary controller; and a plurality of fans operationally connected to the plurality of sensors and configured to draw air toward the plurality of sensors, and wherein the plurality of sensors detect refrigerant, wherein: the auxiliary controller is operatively connected to the primary controller; the auxiliary controller is configured to transmit a first communication, to the primary controller of the transport refrigeration system, indicative of determining at the auxiliary controller that a hazard condition is detected; the primary controller is configured to output a response including communicating an alert and/or engaging in a safety procedure when the primary controller receives the first communication; and the primary controller is configured to engaging the safety procedure by drawing air out of the plurality of compartments with the plurality of fans when the primary controller receives the first communication. the auxiliary controller is operatively connected to the primary controller; the auxiliary controller is configured to transmit a first communication, to the primary controller of the transport refrigeration system, indicative of determining at the auxiliary controller that a hazard condition is detected; the primary controller is configured to output a response including communicating an alert and/or engaging in a safety procedure when the primary controller receives the first communication; and the primary controller is configured to engaging the safety procedure by drawing air out of the plurality of compartments with the plurality of fans when the primary controller receives the first communication.