- Sick Buildings
- Sick Leave
- Side Effects
- Sidewalks
- Sidewall Sprinklers
- Siding
- Sids
- Sign Language
- Signs
- Silicon
- Silos
- Simulation
- Sinkholes
- Sirens
- Situation Awareness
- Situational Awareness
- Six Flags Great Adventure Park Fire
- Size Up
- Ski Patrols
- Skiing
- Skills
- Skin
- Skin Diseases
- Skin Grafting
- Skydiving
- Skylights
- Sleep
- Sludge
- Smartphones
- Smoke
- Smoke Alarm
- Smoke Alarm Programs
- Smoke Alarms
- Smoke Bombs
- Smoke Control
- Smoke Damage
- Smoke Detector
- Smoke Detectors
- Smoke Hazards
- Smoke Inhalation
- Smoke Jumpers
- Smoke Movement
- Smoke Removal
- Smoking
- Smoldering
- Snakebites
- Snow
- Snow Storms
- Social Interaction
- Social Media
- Social Movements
- Social Security
- Social Services
- Social Support
- Social Welfare
- Social Workers
- Society
- Socioeconomic status
- Sociology
- SOG
- Soil
- Soil Conservation
- Soil Pollution
- Solar Energy
- Solar System
- Solid Fuels
- Solids
- Solubility
- Soot
- Sop
- South Canyon Fire
- Soviet Union
- Space
- Space Heaters
- Space Shuttle
- Space Shuttle Columbia Disaster, 2003
- Space Stations
- Space Weapons
- Spacecraft
- Spalling
- Span of Control
- Special Events
- Specialty Teams
- Specifications
- Spectators
- Speed Bumps
- Speed Humps
- Speed Limits
- Spiders
- Spills
- Spine
- Splints
- Spontaneous Combustion
- Spontaneous Human Combustion
- Sports
- Spouse Abuse
- Spray Booths
- Sprinkler
- Sprinkler Sprinklers
- Sprinkler Systems