GHS Pictograms and Classification Guide

GHS pictograms are standardized hazard symbols used globally to communicate specific hazards of chemicals. Each pictogram consists of a symbol on a white background within a red diamond border. This comprehensive guide covers pictogram usage, classification criteria, and precedence rules according to CLP Regulation (EC) No 1272/2008.

1. Basic Pictogram Overview

Explosive (GHS01)

Unstable explosives
Self-reactive substances and mixtures, Types A, B
Organic peroxides, Types A, B
Division 1.1-1.4 explosives

Flammable (GHS02)

Flammable gases, aerosols, liquids, solids (Cat. 1-2)
Self-reactive substances (Types B-F)
Pyrophoric liquids and solids
Self-heating substances
Substances which emit flammable gases
Organic peroxides (Types B-F)

Oxidizing (GHS03)

Oxidizing gases (Cat. 1)
Oxidizing liquids (Cat. 1-3)
Oxidizing solids (Cat. 1-3)

Gas Under Pressure (GHS04)

Compressed gases
Liquefied gases
Refrigerated liquefied gases
Dissolved gases

Corrosive (GHS05)

Skin corrosion (Cat. 1A, 1B, 1C)
Serious eye damage (Cat. 1)
Corrosive to metals (Cat. 1)

Acute Toxicity (GHS06)

Acute toxicity (Cat. 1-3)
Fatal/Toxic if swallowed
Fatal/Toxic in contact with skin
Fatal/Toxic if inhaled

Harmful/Irritant (GHS07)

Acute toxicity (Cat. 4)
Skin irritation (Cat. 2)
Eye irritation (Cat. 2)
Skin sensitization (Cat. 1)
STOT-SE Cat. 3

Health Hazard (GHS08)

Respiratory sensitization (Cat. 1)
Germ cell mutagenicity (Cat. 1A, 1B, 2)
Carcinogenicity (Cat. 1A, 1B, 2)
Reproductive toxicity (Cat. 1A, 1B, 2)
STOT-SE/RE (Cat. 1, 2)
Aspiration hazard (Cat. 1)

Environmental Hazard (GHS09)

Acute aquatic toxicity (Cat. 1)
Chronic aquatic toxicity (Cat. 1, 2)
Hazardous to ozone layer

2. Classification Criteria and Cut-off Values

2.1 Acute Toxicity Classification

Exposure Route	Category 1	Category 2	Category 3	Category 4
Oral (mg/kg)	≤ 5	5-50	50-300	300-2000
Dermal (mg/kg)	≤ 50	50-200	200-1000	1000-2000
Gases (ppmV)	≤ 100	100-500	500-2500	2500-20000
Vapors (mg/l)	≤ 0.5	0.5-2.0	2.0-10.0	10.0-20.0
Dusts/Mists (mg/l)	≤ 0.05	0.05-0.5	0.5-1.0	1.0-5.0

2.2 Skin Corrosion/Irritation Criteria

Category	Criteria	Pictogram
1A	Destruction of skin tissue within ≤ 3 minutes exposure	GHS05
1B	Destruction of skin tissue within > 3 minutes to ≤ 1 hour exposure	GHS05
1C	Destruction of skin tissue within > 1 hour to ≤ 4 hours exposure	GHS05
2	Mean value of 2.3-4.0 for erythema/eschar or edema	GHS07

2.3 Environmental Hazard Classification

Category	Acute Toxicity	Chronic Toxicity	Pictogram
Acute 1	LC50/EC50 ≤ 1 mg/l	-	GHS09
Chronic 1	LC50/EC50 ≤ 1 mg/l	Not rapidly degradable or BCF ≥ 500	GHS09
Chronic 2	1 < LC50/EC50 ≤ 10 mg/l	Not rapidly degradable or BCF ≥ 500	GHS09
Chronic 3	10 < LC50/EC50 ≤ 100 mg/l	Not rapidly degradable or BCF ≥ 500	No pictogram

3. Pictogram Precedence Rules

Key Precedence Rules:

If GHS06 (skull and crossbones) applies, GHS07 (exclamation mark) shall not appear
If GHS05 (corrosion) applies, GHS07 (exclamation mark) shall not appear for skin or eye irritation
If GHS08 (health hazard) applies for respiratory sensitization, GHS07 (exclamation mark) shall not appear for skin sensitization or skin/eye irritation
For substances with multiple hazards, all relevant pictograms shall be used unless specific precedence rules apply

3.1 Multiple Hazard Scenarios

Scenario	Primary Pictogram	Secondary Pictogram	Notes
Acute Tox. (Cat. 2) + Skin Irrit. (Cat. 2)	GHS06	None	GHS07 omitted due to precedence rule
Skin Corr. (Cat. 1) + Eye Irrit. (Cat. 2)	GHS05	None	GHS07 omitted for eye irritation
Flam. Liq. (Cat. 2) + Carc. (Cat. 1)	GHS02	GHS08	Both pictograms required

4. Special Considerations

4.1 Transport Packaging Requirements

GHS pictograms not required on outer packaging when transport pictograms are present
Minimum size requirements: 1 cm² on labels
Must be clearly visible and indelible
Must contrast with background

4.2 Supplemental Hazard Information

Additional EUH statements may be required for specific hazards not covered by standard pictograms:

EUH001: Explosive when dry
EUH014: Reacts violently with water
EUH029: Contact with water liberates toxic gas
EUH066: Repeated exposure may cause skin dryness or cracking
EUH070: Toxic by eye contact
EUH071: Corrosive to the respiratory tract

Important Implementation Notes:

Multiple pictograms may be required for substances with multiple hazards
Precedence rules must be followed when certain combinations of hazards exist
Pictograms must be clearly visible and at least 1 cm² in size on labels
The red diamond border is mandatory for all GHS pictograms
Regular review of classification is required as new data becomes available