SAFETY WORK: CHEMICAL HAZARDS & TOXIC SUBSTANCES

Watch this video to have a short brief regarding safety work: chemical hazards & toxic substances before we learn much more about K3/OSHA on this specific topic ↴

K3 is applied to make the workplace safe, healthy, free of environmental pollution, accidents and work-related illnesses that can reduce work efficiency and productivity.

Chemical hazards and toxic substances: The words hazard and toxic are often used interchangeably in terms of talking about industrial substances or waste. Yet, these words have different meanings, and in order to safely work with them, the difference between both of them should be known. A hazardous substance is one that is ignitable, corrosive, reactive, and toxic. A toxic substance is a substance or waste that when ingested or absorbed can be fatal and harmful to a person.

Chemicals are used by many industries, especially the industries that process and produce chemicals, such as fertilizer, sulfuric acid, soda, explosives, pesticides, paints, detergents, and others.

• LAWS AND REGULATIONS

According to PP 74/2001:

hazardous and toxic substances are substances due to their nature or concentration or amount, either directly or indirectly, may pollute or damage the environment, or may harm the environment, health, human survival and other living things (article 1 point 1). While the objective of chemical hazards and toxic substances management is to prevent and reduce the risk of chemical hazards and toxic substances impact on the environment, human health and other living things (article 2).

• SCOPE/ENVIRONMENT

- The scope of chemical hazards and toxic substances usually includes laboratories, chemical industries, and many other industries that use chemicals as their raw materials.

- Hazardous chemicals can be solid, liquid, vapor, gas, dust, smoke or fog and can enter the body through three main ways:

1. Inhalation: dust, smoke, gas or steam. Some substances, such as fiber can directly injure the lungs.
2. Digestion: Chemicals may enter the body when eating contaminated food with contaminated hands or eating in contaminated environments. The substance in the air can also be swallowed when inhale, as it mixes with mucus from the mouth, nose or throat.
3. Absorption into the skin or invasive contact: Some of these are substances passing through the skin and into the blood vessels, usually through the hands and face.

• CATEGORIES OF CHEMICAL HAZARDS & TOXIC SUBSTANCES

B3 can be divided into two groups: chemical hazards and toxic substances. Hazardous chemicals are chemicals that have reactive properties and are sensitive to changes /environmental conditions which by their nature may pose a hazard to the environment. In general the material can be classified into 5 which consists of:

Flammable substances

Explosives

Reactive substances towards acid and alkali

Poisonous substances

Pressurized gas

• MANAGEMENT OF CHEMICAL HAZARDS & TOXIC SUBSTANCE

Organization for managing chemical hazards and toxic substances involves determining the duties and authority of management personnel, users, and supervisors. In chemical hazards and toxic substances storage, the properties of various types of hazardous chemicals must be known and the chemical reactions due to the interaction of stored materials are also needed to be understand. The interactions consist of: 

1. Interaction between material and environment. Examples: heat/sparks that may cause fire and explosion especially for flammable and explosive substances such as organic solvents and peroxides.
2. Interaction between material and container. Examples: Some highly corrosive chemicals, such as sulfuric acid, chloride acid, sodium hydroxide, can damage the container. This damage causes interaction between materials resulting in dangerous reactions such as fire, explosion or toxicity.
3. Interaction between materials. Example: The interaction between oxidizing agents and reducing agents can cause explosions and fires, whereas the interaction between acid and salt can cause toxic gas. Therefore some materials that may react must be separated in their storage.

• DEVELOPMENT AND MANAGEMENT 

1. Development in knowledge of K3

2. Development with dangerous symbols

3. Prevent/minimize the occurrence of undesirable things such as fire, poisoning, blasting, occupational diseases and other matters that may harm the company, employees, society and the environment.

4. Improve the quality of workforce in employees and workers through K3 field.

• CONTROLLING RISKS

There are a number of ways to control the risks associated with hazardous chemicals.

Some control measures are more effective than others. Control measures can be ranked

from the highest level of protection and reliability to the lowest. This ranking is known

as the hierarchy of control. You must always aim to eliminate a hazard and associated risk first. If this is not reasonably practicable, the risk must be minimised by using one or more of the following approaches:

→ Substitution

→ Isolation

→ Implementing engineering controls

SUBSTITUTION

Substitution is the replacement of a hazardous chemical with a chemical that is less

hazardous and presents lower risks, for example:

1. Substituting a less volatile material to control a vapour hazard may cost less than the

installation and maintenance of a mechanical ventilation system

2. Substituting a highly flammable liquid with one that is less flammable or combustible

3. Using hazardous chemicals with a single hazard class rather than those with multiple

hazards

4. Substituting high hazard chemicals like carcinogens, mutagen, reproductive toxicants

and sensitisers, with less hazardous chemicals

5. Using diluted acids and alkalis rather than concentrates

6. Using a product in either paste or pellet form rather than as dust or powder.

ISOLATION

Isolation involves separating people from the chemicals or hazards by distance or barriers

to prevent or minimise exposure. Examples of isolation include:

1. Isolate workers from chemicals

2. Use of closed systems such as those used during the processing and transfer of

flammable liquids in petroleum refineries, or the use of glove boxes or glove bags

3. Placing a process, or a part of it, within an enclosure which may also be fitted with

exhaust extraction to remove contaminants

ENGINEERING CONTROLS

Engineering controls are physical in nature, including mechanical devices or processes that

eliminate or minimise the generation of chemicals, suppress or contain chemicals, or limit the

area of contamination in the event of spills and leaks. They often involve partial enclosure,

use of exhaust ventilation or automation of processes. Examples of engineering controls

include:

1. Using intrinsically safe electrical equipment in hazardous areas

2. Using robots to minimise operator exposure, for example, spraying in coating operations

3. Partially enclosed and ventilated spray booths or fume cupboards

4. Fully enclosed ventilation booth

5. Local exhaust ventilation to capture airborne contaminants close to their point of release

• STUDY CASE

On the morning of 14 July 2010, chlorine leak incidence was reported at Haji Bunder hazardous cargo warehouse in the Mumbai Port Trust (MPT), Sewri, affecting over 120 people in the neighborhood, including students, laborers, port workers and fire fighters, of whom 70 were reported critical. Sewri yard on one side is adjacent to LBS College of Advance Life Time Studies and Research, while a vast area of sea and vacant land lies on the other side. The leak was observed at nearly 3:00 a.m. Many students from LBS College hostel that is barely 100 m from the site of leak were affected. Those who were sleeping were the most affected and they started vomiting. Examination saved many students who were awake and studying. Suddenly, they felt suffocated and they saw outside their rooms a blanket of smoke in the yard where chlorine cylinders were kept. By 4:00 a.m., the hostels were completely evacuated. Police vans and ambulances took the victims to the hospital where it took few hours for the clinical symptoms of the victims to subside. The Mumbai Police has registered gas leakage case against unidentified persons.

Chlorine, under ordinary conditions of temperature and pressure, is a greenish yellow gas with a characteristic pungent smell and suffocating odor. Gaseous chlorine is approximately 2.5 times heavier than air. Liquid chlorine is clear amber in color and 1.5 times heavier than water. Chlorine reacts readily with lime and caustic soda to form hypochlorites. Hence, lime and caustic soda solutions are generally used for handling chlorine leaks.

Chlorine gas is a primarily a respiratory irritant. It is extremely irritating to the mucous membrane, the eyes and respiratory tract. The threshold limit values (TLV) of chlorine is 1 ppm or 3 mg/m3 of air. If the duration of exposure or the concentration of chlorine is excessive, it causes restlessness, throat irritation, sneezing and copious salivation. In extreme cases, lung tissues may be attacked, resulting in pulmonary edema. The revised Immediately Dangerous to Life or Health (IDLH) is 10 ppm and the fatal dose is 1000 ppm.

The prolonged symptoms intolerable to patient might lead to possibilities of pulmonary embolism, denudation of alveolar and bronchial epithelium, pulmonary edema, chemical pneumonitis, alveolar disruption and, as a rare complication, pneumomediastinum. This rare complication needs to be understood for providing immediate care to the victims in the proper way. In case of acute exposure, it may lead to acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS) due to which 1% of the patients might die. Humidified oxygen and inhaled β-adrenergic agents are appropriate therapies for victims with respiratory symptoms while assessments are underway. Inhaled bicarbonate and systemic or inhaled glucocorticoids also have been reported anecdotally to be beneficial. However, it is still at an experimental level and requires further clinical evidence prior to its universal utility.

It was learnt that the chlorine cylinders have been abandoned by an importer nearly a decade ago in 1997 and MPT has been unsuccessful in selling off these cylinders. According to MPT officials, the leak occurred from one of 141 cylinders stored at the storage place. For over 6 hours, rescue and relief teams struggled to control the situation and it took fire officials, Bombay's Municipal Corporation teams, and experts from Herdillia Chemicals, Rashtriyia Chemicals and Fertilizers, Century Rayon and Mutual Aid Response Group, to identify, seal, and clamp the leaking of other cylinders. Fire fighters created water curtains in the area diluting the gas cloud that was spreading because of the leakage. The air pressure thus created helped the clouds of chlorine to float toward the sea. The neutralization process of the remaining chlorine filled cylinders using caustic soda and water was carried out by the National Disaster Response Force (NDRF) and other emergency responders. Out of 105 cylinders that had been found, 100 were clean but five of them had residual chlorine that leaked out. On an average, 6 hours had been consumed in cleaning one cylinder. In all, 16 out of 100 cylinders were neutralized. It was noticed that MPT did not have a chlorine neutralization tank, which every establishment that stores and uses chlorine maintains, to control such conditions. It was also observed that no safety guidelines were observed or safety systems maintained at the facility.

The need for knowledge about chemical factors along with their classification becomes very important considering there are many accidents in industries especially those that use hazardous and toxic chemicals. With the knowledge and understanding of chemical factor as a whole we hope to reduce the rate of work accident especially from chemical factors in the workplace.