PMLS T10 - Laboratory_Waste_Management_Services_and_Disposal_System

Waste

any discarded material

Laboratory Waste

Materials used to sustain laboratory operations that are no longer needed and should be discarded

Classification of Laboratory Wastes

Hazardous and Nonhazardous wastes

Nonhazardous wastes

materials that do not contain hazardous components, such as, pipette tips, test tubes, flasks, petri dishes, microtitre plates, gloves, and empty plastic chemical containers

Characteristics of Hazardous Wastes

● Explosivity and Reactivity

● Corrosivity

● Toxicity

● Ignitability

Explosivity and Reactivity

Unstable waste that reacts violently when exposed to chemical change; the type to release toxic fumes when mixed with water and could explode

Corrosivity

Waste that needs to be separated from othere wastes; reacts with heavy metals; corroodes steel waste containers ad aqueous substances with pH<2 or P.12.5

Toxicity

Waste that is harmful to both humans and environment as it stimulates the leaching of materials from a landfill into the surrounding groundwater; may cause acute health effects, such as, rashes, headache, nausea or burns that can be reversible once exposure stops

Bioaccumulation

The absorption and retention of toxic substances in the body; the increase of contaminant concentration

Ignitability

Waste that can cause fire during waste disposal or storage

Flash Point Test

measures the lowest temperature at which a liquid or volatile material gives off enough vapor to form an ignitable mixture with air when an ignition source is introduced

Categories of Laboratory Waste

1. Infectious Waste

2. Pathological Waste

3. Chemical Waste

4. Radioactive Waste

5. Biomedical Waste

Infectious Waste

Waste that contains pathogenic microorganisms

Ex. cultures of bacteria, contaminated sharp objects (syringes), gloves, bandages from venipuncture

Pathological Waste

Waste including human and animal tissues, organs, body parts (excluding teeth, hair and fingernails), and body fluids that are removed during autopsy, biopsy, surgery or other medical procedure

Chemical Waste

Discarded solids, liquids and gaseuos chemicals from laboratory procedures including laboratory reagents

Radioactive Waste

Wastes containing radioactive substances such as chemical reagents

Biomedical Waste

Waste containing infectious or potentially infectious materials generated during treatment or procedures

Ex. human anatomical wastes (tissue organs and body parts), microbiology wastes, sharp objects and material contaminated with blood (surgical dressings and swabs) and chemical waste

Occupational hazards

exposure to biomedical waste causes potential hazard to heathcare workers

Biohazard symbol

should be three-fourths full at maximum, covered in a puncutre-resistant double bag as a container, and placed inside a leak-proof drum or bin

Hazard

anything that has potential to harm or can adversely affect the health of healthcare workers

Risk

refers to the possibility of suffering the adverse health effects of hazards

Ex. Hazard - Risk

Gasoline - Lightning a match; Driving - Texting

Color-coded System of Segragating Biomedical Waste

Red (Syringe)

Blue (Broken glassware, sharp objects, needles, scalpel)

Yellow (Highly infectious items like human anatomical wastes, items containing bood, body fluids, microbiological wastes)

Black (Chemical wastes)

Diagnostic reagents

chemical substances used in a clinical laboratory

Safety Data Sheets

Provide information on the hazards of the chemical components

Chemical Safety Data Sheet (CSDS)

Catalogue that gives information on handling, storage, toxicity, health effects, first aid, reactivity, protective equipment, and spill-handling procedures; Includes safety symbols

Safety Symbols

Conveys information related to the nature of hazards

Ex. flammable, oxidizing, toxic, corrosive, explosive, general warning, dangerous for the environment, health hazard, and gas cylinder

Hazardous Materials Identification System (HMIS)

An identification code developed by the American Coatings Association as a compliance aid for OSHA

Numerical Ratings (0-4)

BLUE: health hazards

RED: flammability

ORANGE: physical hazard

WHITE: personal protection

4: life-threatening

Chemical Waste Disposal

Incompatible chemicals should not be stored in the same containers

OXIDIZERS — don’t mix with reducing agents or organic materials

ACID-REACTIVE — don’t mix any acids

ORGANIC ACIDS — segregate from inorganic acids

ACIDS — don’t mix cyanide salts or cyaanide solutions

OXIDIZING ACIDS — can’t be stored with combustive materials

OXIDIZING AGENTS — don’t mix reducing agents

ALKALI METALS — keep separate from water

Chemical Waste Storage

preferred types of containers: drums and jerricans

common types of material for chemical wastes: plastics and steel

Laboratory Waste Management

aims to prevent the spread of diseases and the leaching of hazardous chemicals into groundwater;

Note: 75%-90% of waste poses no risk of infection

Types of Hazardous Wastes

● Infection-associated waste

● Pathological waste

● Sharp objects

● Pharmaceutical wastes

● Heavy metal wastes

● Radioactive wastes

Means of Waste Disposal

● Incineration

● Pyrolysis & Gasification

● Microwave Treatment

● Autoclave

● Plasma-Based Systems

● Irradiation

● Sterilization

● Sewer Systems

Incineration

The most acceptable means of waste disposal; Carbon-dioxide, water, oxides of sulfur and nitrogen and other volatile materials can be emitted

Best disposed through Incineration:

● Blood and its containers

● Tissue specimens in sealed biohazard bags

● Non-glass disposable tubes

● Swabs

● Pipette tips in sealed biohazards bags

● Syringes

● Needles

Pyrolysis

Medical waste that does not contain radioactive materials; Thermal decomposition of organic material into ash, ___ oil, and synthetic gas (syngas); Requires no oxygen

Gasification

The carbon left can be converted to syngas; Thermal process requires little amount of oxygen

Microwave Treatment

Medical wastes are shredded, which reduces the volume by up to 80%, then it is mixed with water before being subjected to microwaves;

Autoclave

Commonly used in the laboratory to sterilize bacteria present in clinical wastes; Destroys bacteria through the high-pressure steam

Plasma-Based Systems

Uses high-temperature ionized gas to convert waste to a compact substance

Irradiation

Used to sterilize medical wastes through exposure to cobalt source; Gamma radiation; expensive

Sterilization

Involves heating with saturated steam to kill all forms of microbial life

Sewer Systems

Waste discharged into the sewer drains; Water-soluble substances, flammable solvents, acids, and alkali should be diluted with water before pouring; this method has a lot of exceptions and isnt often recommended

Proper Hazardous Waste Disposal Procedures

- Container should be non-leaking with a non-leaking lid
A. Sink Disposal

B. Trash Disposal

Sink Disposal

Prohibited for hazardous wastes; Only allowed if the drainage system is connected to a wastewater treatment plant

Trash Disposal

Discard non-hazardous wastes and labelled appropriately so

Proper Handling of Hazardous Wastes

A. Labeling of Waste

B. Segregation of Waste

C. Storage of Waste

D. Capping Waste Bottles

E. Accumulation of Excessive Wastes

Labeling of Waste

● All waste bottles should be labeled properly as “Hazardous Waste“

● Labeling is only acceptable in words

● Labels of old containers should removed or defaced

Storage of Wastes

● Do not store waste in a fume hood

● Do not use metals cans

● Use polyethylene containers

● Waste bottles are stored away from a sink or floor drain

Capping Waste Bottles

● Capped in order to prevent release of contents

● Don’t cap too tightly to avoid build up of pressure inside the bottle

Accumulation of Excessive Wastes

● Only one type of container of each type of waste should be in the laboratory

● A full organic waste bottle should be sent to the stockroom for disposal

Guidelines in storing waste:

• Don’t store close to each other

a. Acids and bases

b. Organic materials and acids

c. Cyanides, sulfides, arsenic compounds, and acids

d. Powdered or reactive metals and combustible materials

e. Mercury, silver, and ammonium compounds

Waste Containers Guidelines for Segregation in the Laboratory

a. Solid, with no cracks, rust, or deterioration

b. Compatible with waste

c. Properly labeled with full chemical name and approximate percentage of each component

d. Fitted with a cap at all times located in the laboratory

Biomedical Wastes Segragation Guidelines in the Laboratory

a. Patient

b. Care activity areas

c. Diagnostic services

d. Operating rooms

e. Delivery rooms

f. Treatment rooms

g. Biomedical wastes must be collected within 24 hours

h. Trolleys and carts or desiccated wheeled containers used for transport are cleaned and disinfected

i. During transport, the wastees should not pass through patient care areas

Solid waste, contaminated and uncontaminated organs, tissues, carcasses, and beddings

Placed in large biohazard bags and inform the management handling section

Plastic petri dishes, tissue cultures, containers with and without liquid media, contaminated gloves, towels, etc.

can be sterilized or placed in biohazard plastic bahs that are securely taped with sturdy waterproof plastic tape

Liquid waste

autoclaved or sterilized and discarded in a sanitary drain

Sharp objects

placed in a light plastic sharps container, securely taped and closed

Carcinogens and chemotherapeutic agents

kept in polyethylene bags designed for cytotoxic waste disposal, sealsed and disposed of via burning the boxes

Physical Process Treatment of Hazardous Laboratory Waste

● Solvent Extraction

● Sedimentation

● Floatation

● Drying

● Evaporation

● Filtration

● Sludge dewatering

Chemical Process Treatment of Hazardous Laboratory Waste

● Solvent Extraction

● Neutralization

● Oxidation-reduction

● Hydrolysis

● Electrolysis

● Precipitation

Common Errors Encountered in Handling Hazardous Laboratory Wastes

1. Failure to label the waste container

2. Improper labeling of the waste container

3. Failure to close/seal the waste container

4. Improper segregation of the wastes

5. Improper stoarage of the wastes

6. Using an improper waste container

7. Accumulation of too much wastes

Carcinogens

Substances that can induce the onset of cancer

Ex. benzene, arsenic, vinyl chloride, acrylonitrile, asbestos, 1,3-butadiene alphatoxins, cadmium, or benzidine

Pharmaceutical Waste

Pharmaceutical products, drugs, or chemicals returned from wards, spilled, outdated, or contaminated