Module 8: Hazardous Substances Management

The proper handling of chemical and biological agents is essential to prevent occupational diseases and protect the environment. Technical knowledge of these substances allows for the anticipation of risks that are often invisible.

8.1 Classification and Labeling (GHS)

Hazard identification is performed through the Globally Harmonized System (GHS). Labels must be legible and provide immediate information regarding the nature of the risk.

Category	Examples	Nature of Hazard
Environmental Hazard	Pesticides, used oils	Contamination of soil and aquifers
Corrosive	Acids (hydrochloric), bases (soda)	Destruction of living tissue and metals
Harmful / Irritant	Diluted solvents, varnishes	Allergic reactions and inflammation
Toxic	Methanol, carbon monoxide	Severe systemic damage or lethal effects
Flammable	Gasoline, ethyl alcohol	High ignition capacity
Oxidizing	Pure oxygen, peroxides	Violently accelerate fires
Explosive	Dynamite, certain pressurized gases	Sudden release of energy

8.2 Exposure Control Hierarchy

When a hazardous substance is present, action must be taken following a technical order of priority:

Substitution at Source: Replace the substance with a less hazardous one or modify the process to eliminate chemical use.
Technical and Collective Measures: Installation of local exhaust ventilation systems, general ventilation, or process isolation.
Personal Protective Equipment (PPE): Use of respirators with specific filters, chemical gloves, and protective suits only when previous measures are insufficient.

8.3 Limit Values and Sensory Perception

Exposure Limit Value (ELV): The maximum concentration of a substance in the air to which a worker can be exposed without suffering harm.
Odor Threshold: The ability to detect a substance by smell.
Critical Warning: Many lethal gases, such as Carbon Monoxide (CO), are odorless, colorless, and tasteless. Never rely on smell; the use of calibrated gas detectors is mandatory.

8.4 The Risk of Asbestos

Asbestos is a fibrous material that is highly carcinogenic when its particles become airborne.

White Asbestos (Chrysotile): Moderate/high risk.
Brown Asbestos (Amosite): High risk.
Blue Asbestos (Crocidolite): Extreme risk.

Protocol: Any handling of materials suspected of containing asbestos must be performed by specialized companies under strict decontamination protocols.

8.5 Oxygen Concentrations in the Air

Oxygen levels are critical for safety, especially in confined space work.

21%: Normal concentration in the air.
Below 19%: Oxygen deficiency. Risk of asphyxiation, loss of consciousness, and death.
Above 23%: Oxygen enrichment. Extreme risk of fire and spontaneous explosion of materials.

8.6 Industrial Gas Cylinders

Pressurized gas bottles combine chemical and mechanical risks.

Storage: Must always be in an upright position, secured with chains, and protected from direct sunlight.
Segregation: It is mandatory to separate flammable gas cylinders from oxidizing gases (such as oxygen) to prevent reactions in case of a leak.
Color Coding: The shoulder (top part) of the bottle indicates the type of gas it contains according to current regulations.

8.7 Biological Risks

These refer to exposure to microorganisms such as bacteria, viruses, and fungi.

Routes of Entry: Respiratory, digestive (ingestion), dermal (skin), or parenteral (wounds/needlesticks).
Preventive Measures: Vaccination programs, rigorous personal hygiene, and use of specific PPE.