A method of determining the presence of a chemical in an environment, the method comprising: receiving, by an exposure application stored in a non-transitory memory and executed on a processor , a plurality of sensor readings from a plurality of chemical sensors via a communication device associated with an individual, wherein each chemical sensor of the plurality of chemical sensors is configured to detect a different chemical; determining, by the exposure application , a cross-sensitivity pattern from a chemical or a combination of chemicals in the plurality of sensor readings; comparing, by the exposure application , the cross-sensitivity pattern with one or more known chemical patterns of a chemical or combination of chemicals; determining that the cross-sensitivity pattern matches one of the one or more known chemical patterns; and identifying a chemical or combination of chemicals giving rise to the cross-sensitivity pattern based on determining that the cross-sensitivity pattern matches the one of the one or more known chemical patterns; characterized by : detecting, by the communication device , the presence of personal protective equipment and compliance with proper use of said personal protective equipment by the individual; and determining a chemical exposure level of the individual to the identified chemical or combination of chemicals giving rise to the cross-sensitivity pattern; when it is determined that the chemical exposure level of the individual to the identified chemical or combination of chemicals giving rise to the cross-sensitivity pattern exceeds an exposure threshold for the individual, sending to the communication device a warning on the presence of said identified chemical or combination of chemicals including a notification to use a particular type of personal protective equipment. receiving, by an exposure application stored in a non-transitory memory and executed on a processor , a plurality of sensor readings from a plurality of chemical sensors via a communication device associated with an individual, wherein each chemical sensor of the plurality of chemical sensors is configured to detect a different chemical; determining, by the exposure application , a cross-sensitivity pattern from a chemical or a combination of chemicals in the plurality of sensor readings; comparing, by the exposure application , the cross-sensitivity pattern with one or more known chemical patterns of a chemical or combination of chemicals; determining that the cross-sensitivity pattern matches one of the one or more known chemical patterns; and identifying a chemical or combination of chemicals giving rise to the cross-sensitivity pattern based on determining that the cross-sensitivity pattern matches the one of the one or more known chemical patterns; characterized by : detecting, by the communication device , the presence of personal protective equipment and compliance with proper use of said personal protective equipment by the individual; and determining a chemical exposure level of the individual to the identified chemical or combination of chemicals giving rise to the cross-sensitivity pattern; detecting, by the communication device , the presence of personal protective equipment and compliance with proper use of said personal protective equipment by the individual; and determining a chemical exposure level of the individual to the identified chemical or combination of chemicals giving rise to the cross-sensitivity pattern; when it is determined that the chemical exposure level of the individual to the identified chemical or combination of chemicals giving rise to the cross-sensitivity pattern exceeds an exposure threshold for the individual, sending to the communication device a warning on the presence of said identified chemical or combination of chemicals including a notification to use a particular type of personal protective equipment. <EOS>