Hazard Levels (1

Understanding the 5-level hazard classification system used to indicate overall chemical danger in your library.

NextSDS rates a product's intrinsic hazards based on the classification in section 2 of the SDS (GHS/CLP). The hazard is expressed using five hazard levels where the most hazardous products score 5 and the least hazardous score 1.

Level	Label	Description
5	Extreme	Highest severity across one or more categories. Severe or life-threatening hazards present.
4	High	Serious risks in one or more categories. Significant health, environmental, or safety hazards.
3	Moderate	Moderate risks present. Noticeable health, environmental, or safety concerns requiring precautions.
2	Low	Minor risks present in one or more categories. Low severity effects possible.
1	Minimal	Negligible risk across health, environment, and safety. Safe under normal use.

The overall level is the maximum of three sub-scores: Health, Environmental, and Safety. See How hazard levels are calculated for the H-code mapping behind each one.

Level 5: Extreme

Category	Description
Health	Fatal if swallowed, inhaled, or upon skin contact. May cause cancer, genetic defects, or damage to fertility.
Environmental	Very toxic to aquatic life with long-lasting effects. Accumulates in nature and organisms. Ozone depletion and widespread water contamination.
Safety	Explosive, even without air. Severe fires, blast hazards, or violent reactions.

Level 4: High

Category	Description
Health	Toxic via all routes. Serious burns and eye damage. Allergic reactions. Organ damage or long-term health issues.
Environmental	Very toxic or toxic to aquatic life and some land species. Suspected endocrine disruption.
Safety	Extremely flammable gases, liquids, and aerosols. Explosive when heated. Violent reactions with air, water, or chemicals.

Level 3: Moderate

Category	Description
Health	Harmful via all routes. Eye irritation and mild organ damage. Allergic reactions possible.
Environmental	Toxic or harmful to aquatic life with possible long-lasting effects.
Safety	Flammable gases, liquids, and solids. Pressurised gases. Self-ignition or dangerous reaction with water possible.

Level 2: Low

Category	Description
Health	Mild skin or eye irritation. Dizziness, drowsiness, or respiratory irritation. Risks from repeated exposure.
Environmental	Harmful to aquatic life, but less severe than higher levels.
Safety	Flammable liquids and gases, but generally less intense hazards.

Level 1: Minimal

Category	Description
Health	Mild skin irritation in rare cases. Safe if handled properly.
Environmental	No significant environmental impact.
Safety	No special safety hazards under normal conditions.

Where it appears

Library table: as a colour-coded indicator in the "Hazard Level" column
Hover tooltip: shows the overall level plus Health, Environmental, and Safety sub-scores

What to do next

Filter your library by hazard level to find the products that need attention first, then run an EMKG risk assessment on them.

Hazard Levels (1–5)