Chapter 6 - Biological & Chemical Agents

Work Practices

-all employees must be properly trained in the identification and handling of dangerous substances -senior management must ensure that policies and procedures are accompanied by an appropriate discipline system for dealing with those employees who willfully neglect these practices

Skip Absorption

-chemical contact with the skin is a common occurrence, common types of injuries include: 1. chemicals not absorbed through skin may produce localized irritation (dermatitis) 2. burns or blisters (chemical action) 3. skin disorders (biological action) 4. skin damage (physical action

WHMIS

-comprehensive communication system outlining the safe use of hazardous products via: 1. product labels 2. safety data sheets 3. worker education and training -updated in 2015 to reflect new rules related to classifying hazards, label requirements, and newly formatted safety data sheets

Administrative Controls

-employees should receive training in: safe operating and emergency procedures, use and care of PPE, handling and control of agents (chemical & biological) -training must be conducted on an ongoing basis, given that new solvents and other agents are continually entering the workplace

Materials Safety Data Sheets

-identify potentially harmful materials -present information about the nature of material and their harmful effects -provide guidance on how to handle safely

Diseases resulting from biological agents

-legionnaires' disease -AIDs -SARs

Personal Protective Equipment (PPE)

-most commonly used protection device is a respirator -PPE for hands, face, and other bossy parts must be provided where neccessary -inhalation is the most common and hazardous route of entry -no single protective device, such as a face mask, will adequately address all conditions for all workers -device must be properly fitted to individual

Respiration

-most human exposure to chemicals comes from breathing airborne contaminants -respiratory system does a very efficient job of distributing these contaminants throughout the body during the normal air exchange process -5 basic levels of protection in respiratory tract: nose, interior of the nasal passage, mucus/cilia, lung passage, alveoli

Penetration

-occurs when skin is cut or punctured by any sharp object -the type of contamination on the source, such as a knife, will determine the possible trauma or illness

Engineering

-one of the best ways to reduce the risks associated with handling solvents is to find alternative -substitution with less hazardous solvents -process enclosure ventilation -closed systems

Ingestion

-poor personal hygiene, eating, drinking, or smoking in an area where solvents are used can contribute to poising. Types of injuries include: 1. solvents causing damage to the digestive system 2. solvent may be absorbed into bloodstream and carried to organs

Medical Surveillance

-pre-employment and pre-placement medical examinations should be conducted to establish a baseline of the employee's health and exposure to agents in previous workplaces -follow-up medical examinations should be conducted periodically -record keeping is an important aspect -types of exposures employees face and their health records before and after exposure should be included in their process

Toxicology

-study of poisions -study of chemical-related occupational illnesses

Inorganic Solvents

-the difference between an acid and a base is expressed in terms oh pH

Personal Hygiene Practices

-the ingestion of chemical or biological particulate is often the result of poor hygiene -individuals who handle agents without wearing proper protective gear, such as gloves, are at risk of food contamination -remove outer protective clothing, and clean hands, arms, face, and nails before entering rest areas or lunchrooms -avoid touching lips, nose, eyes -wash hands before eating, drinking, smoking

Two Classes of Inorganic Solvents

1. Acids (hydrochlroic acid, sulphuric acid, chromic acid - high corrosive, used for refining metals, health effects include burns resulting from inhalation and skin contact) 2. Bases (potassium hydroxide, sodium hydroxide - all are toxic in certain concentrations)

3 Methods of Controlling Exposure

1. Engineering 2. Work Practices 3. Medical

Four Routes Chemicals Enter the Body

1. Respiration (inhalation) 2. Skin Absorption 3. Ingestion 4. Skin Penetration

Two Specific Types of WHMIS Labels

1. Supplie 2. Workplace Labels

Toxicity

ability to cause injury to human biological tissue

Aersols

airborne respirable contaminants, such as liquid droplets or solid particulate, dispersed in air, that are of a fine enough particle size to remain suspended for a time

Susceptible Host

an individual or animal that becomes infected with a biohazards agent

Agents

any substances, chemical or biological, to which a human may be exposed at work or at home

Chemical Agents

hazards created by exposure to chemicals

Biohazards

hazards created by exposure to infectious microorganisms, proteins, or nucleic acids

Physiological Reactions to Low Level Chemical Exposures

headaches, dry nasal passages, and nausea

Biological Agents

natural organisms or products of organisms that present a risk to humans

Synergistic Effect

occur when the result of two factors taken together is greater than the sum of the two (e.g., a lifestyle factor such as smoking can have synergistic effect on some material)

Reservoir

the home or environment where the biological agent grows and multiples

Mode of Trasmission

the means or channel by which an agent is carried from one host to another

Portal of Exit

the path by which a biohazards agent leaves its host

Chain of Infection

the process and conditions by which biological agents are spread from one host to another

How to determine the seriousness of a hazard

toxicity (e.g., its ability to cause injury to human biological tissue)