topic 2: Occupational Hazards/Biosafety Levels Flashcards
1
Q
physical hazards
A
- animal bites/scratches
- flammable materials
- low lighting in animal rooms
- inadequate housekeeping
- sharps
- radioactive materials
- ergonomic demands
- noise
2
Q
animal bites/scratches: how can it be avoided? what to do?
A
- proper training in animal handling techniques
- be aware of environmental factors intrinsic to the animal
- have knowledge of animal behaviour
- if bitten, cleanse thoroughly with running water and soap
- identify the animal and report to the veterinarian who may choose to quarantine the animal
- report to the supervisor and seek further medical attention if needed
- record details of the accident in the Accident Reporting Form
3
Q
flammable materials: classes of fires
A
- class A fire: generable combustible material such as wood, paper, cloth e.g. bedding, paper gowns, plastic cages, etc.
- class B fire: flammable gases and liquids such as oil & paint, e.g. flammable solvents used for cleaning floors & sterilising equipment
- class C fire: flammable gases, liquids, & electric equipment, e.g. lightning, wet vacuums, automatic cage-washers, etc.
- class D fire: combustible metals such as magnesium, sodium and potassium
4
Q
low lighting in animal rooms: why is the lighting low? what hazards does it pose?
A
- in animal care rooms, light cycles may vary and most animals receive only artificial light
- animals may be kept in rooms with single-colour lights (typically red) or very low light
- poor lighting = visual fatigue or safety hazards e.g. trips, slips & falls
- humans need adjustment periods for the eyes to become accustomed to the colour or light level in the rooms
5
Q
sharps: how to mitigate the hazard?
A
- install puncture-resistant and leak proof containers for sharps (sharps bin)
- appropriate restraint or sedation of the animal during procedures entailing the use of sharps
- properly dispose of sharps in official sharps bins
- never recap a needle unless necessary (if necessary, use the one handed method or recapping device)
6
Q
radioactive materials: what are the hazards? how to mitigate?
A
- radiation (radionuclides) can present hazards through inhalation, ingestion, skin contact & proximity
- outside the body = external hazard
- ingested, inhaled or absorbed = internal hazard
- label animal cages with coloured tape containing the appropriate logo
- caution signs on animal room doors listing the radioisotope being used & name of the principal investigator (PI)
- personnel must not handle irradiated animals or bedding unless they have proper radiation safety training
- proper disposal plan for irradiated animals/bedding
7
Q
ergonomic demands: what are they? how to mitigate?
A
- injuries that result from repetitive small stresses (cumulative injuries, e.g. carpal-tunnel, tennis elbow, back injuries)
- vary tasks to lessen repetitions (take short breaks to stretch, or do another activity involving another set of muscles)
- re-engineer tasks or re-design equipment to require fewer repetitions with less strain
- anyone lifting heavy loads should be physically fit, avoid any sudden movements and use a 2-handed lifting technique
- use of lifting equipment, automation or splitting the load can reduce the risk of injury
8
Q
noise: what are the hazards? how to control the hazard?
A
- chronic noise-induced hearing loss, speech difficulties, loss of concentration, increased fatigue and distraction
- OSHA limits employee exposure to noise to 90 decibels measured on the A scale of a standard sound-level metre at slow response (dBA) averaged over an 8 hour shift
- if levels exceed 85 dBA, exposed employees must participate in a hearing-conservation programme
- the programme includes monitoring, audiometric testing, hearing protection, training & record-keeping
- can occur in cage washing areas or dog/pig holding units
- apply engineering controls, administrative controls or PPE (e.g. earplugs, earmuffs) to control the hazard
9
Q
chemical hazards
A
- flammability, corrosiveness, reactivity, explosivity and toxicity are the hazardous properties of chemicals
- e.g. carcinogens, allergens, irritants, mutagens & teratogens
- sources of exposure include disinfectants, pesticides, volatile anaesthetic gases & chemicals for preserving tissues (e.g. chlorox, acids, aldehydes, formalin)
- controlled drugs & items of potential abuse (e.g. ketamine)
- monitor the exposure to waste anaesthetic gases in operating rooms
- burns & irritations of the skin are the most common chemical injury associated with animal care and use
- adopt good practices, use PPE & safety equipment
- label all chemicals & store them in safe places
- install safety devices such as eye-wash stations & fume cupboards
- be familiar with the chemicals being used by consulting the Material Safety Data Sheet (MSDS)
- MSDS available in cage wash areas that describe each chemical used, the hazard it poses & procedures to follow in case of exposure
10
Q
biological hazards
A
- allergies & zoonotic diseases (e.g. blood borne pathogens, body fluids, animal skin, etc.)
- must be clearly indicated by standard biological warning signs giving the type & degree of risk and the person responsible (e.g. danger - infectious materials)
- infection may be acquired via ingestion, inhalation, eye contact, skin lesions or bites (animals can be a source)
- cages & racks should be demountable, autoclaveable & labelled to indicate their infectiousness
- all refuse & carcasses must be disposed of carefully, preferably by autoclaving & incineration
- sterilisation facilities should be available in an animal house
11
Q
zoonotic diseases…
A
- potential hazard to researchers/technicians when they work with animals
- rare when working with animals bred for research as opposed to wild caught animals, but still possible especially if the experiment involves diseases & infected animals
- personal hygiene is a critical barrier to the transmission of zoonoses, must be reinforced regularly!
- keep lab animals SECURED against wild rodents (to prevent breeding)
12
Q
haemorrhagic fever with renal syndrome (HFRS)
A
- Hanta RNA virus (Bunyaviridae)
- typically transmitted by striped field mice but there are also similar viruses found in other rodents
- transmitted by aerosol
- rodent respiratory secretions, saliva, urine, faeces, animal bites, when dried materials contaminated with rodent excreta is disturbed
- contaminated wounds, conjunctival exposure or ingestion
- initial symptoms begin suddenly: intense headaches, back & abdominal pain, fever, chills, nausea, blurred vision
- later symptoms can include: low blood pressure, acute shock, vascular leakage, acute kidney failure (causing severe fluid overload)
- mortality rate of HFRS is around 5-15%
- must be handled in BSL 3 or 4 labs
13
Q
lymphocytic choriomeningitis (LCM)
A
- caused by Arena ssRNA virus
- associated with Lassa fever & Argentine and Bolivian haemorrhagic fevers
- infected naturally: mice, hamsters, guinea pigs, nonhuman primates, swine, dogs
- transmission is by inhalation or contamination of mucous membranes/broken skin with tissue/fluid of an infected animal (e.g. contaminated bedding materials/fomite, can be in utero or early in neonatal period)
- symptoms similar to influenza-like disease, progressing to meningitis & coma
- can be treated
- mortality rate is less than 1%
14
Q
murine typhus (a.k.a endemic typhus)
A
- caused by rickettsia typhi bacteria in rats
- often confused with viral illnesses
- transmission by aerosols/accidental parenteral inoculation/bites from natural ectoparasitic vectors
- symptoms: fever, headache with encephalitis (inflammation of active brain tissue), myalgia and a rash
- death may occur in the elderly, severely disabled, or patients with a depressed immune system
- highly treatable with antibiotics e.g. tetracyline and chloramphenicol
15
Q
rat bite fever
A
- caused by gram negative bacteria streptobacillus moniliformis or spirillum minor present in oral and respiratory passages of rats
- transmission by bites/scratches/ingestion of contaminated products/urine/bodily secretions of an infected animal
- asymptomatic in rats
- symptoms: diarrhoea, hepatitis, septicemia (sepsis), arthritis, haemorrhage in mice
- in Strep. moniliformis infection, patients develop chills, fever, malaise, headache, muscle pain and then a maculopapular or petechial rash
- arthritis occurs in 50% of Strep. moniliformis cases
