12 complete symptom paths42 guides and 60 questions in each1,460 Grade A articlesOne searchable, connected knowledge library140 official sourcesEvidence context with explicit limits
Smell the pathway

Smell Atlas

Follow the pathway, not only the label.

Onset, duration, airflow and nearby systems often separate moisture, drainage, combustion and electrical sources.

Describe your clue →
Combustion product01

Smoke odor without visible smoke

Unexplained smoke odor requires immediate fire and combustion assessment.

Trigger
fire, appliance or backdraft
Strongest location
any occupied area
Open signal profile →
Sensory method

Describe first. Interpret second.

  1. TriggerWhat changed immediately before it began?
  2. CycleDoes it follow startup, flow, heating, wind or room use?
  3. LocationWhere is it strongest, and does that move?
  4. Stop conditionHeat, smoke, gas or electrical odor changes the response immediately.