A Practical G

uide Specifically for Frontline Workers

Biological Hazards – Prevention and Personal Protection

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Contents

1. What is biological hazard?

2. Occupations and workplaces where people

may come into contact with biological hazards

3. Preventive and control measures

4. Respiratory protection

5. Protective clothing

6. Goggles / Face shields

7. Gloves

8. Shoe covers

9. Sterilization

10. Personal hygiene

11. Conclusion

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As corona virus, the cause of Atypical Pneumonia,rampages over Hong Kong, i t has broughtunprecedented challenge to the safety and health of thefrontline workers in the medical profession, healthcareservices, cleaning service and property management.These frontline workers remain steadfastly at their postsduring this very difficult time are under the constant threatof the killer virus. The Occupational Safety and HealthCouncil has prepared this Practical Guide to provideguidance on the proper use of personal protectiveequipment and the sterilizing agents, so that thesededicated workers can protect themselves adequatelyin the fight against this biological hazard.

1. What is biological hazard?

Biological hazards refer to organisms or organic mattersproduced by these organisms that are harmful to humanhealth. These include parasites, viruses, bacteria, fungiand protein. In general, there are three major of routesof entry for these micro-organisms into our body, i.e.through the respiratory system, transmission throughcontact with body fluids of the infected or contact withcontaminated objects. The harmful effects posed tohuman health by these biological hazards are mainly ofthree types - infections, allergy and poisoning.

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2. Occupations and workplaces where peoplemay come into contact with biological hazards

• Medical staff, cleaning staffand laboratory technicians inthe medical profession;

• Healthcare services;

• C l e a n i n g s e r v i c e s a n dproperty management;

• Employees in environmental hygiene services such asliquid waste and rubbish collection and disposal;

• Agriculture, fishery, veterinaryservices, and manufacturingindustries that use plant- or animal-based raw materials, such as paperand paper products, textile, leatherand furs and related products;

• Indoor workplaces like entertainment premises,restaurants and hotels, where employees generallywork in enclosed areas with central air-conditioning: –Any microorganismbreeding inside theair-conditioning systemor cool ing towersmay spread in theworkplace through theair-conditioning system.In the office building,the furnishing materialsl ike carpets and wall-papers, the potted plantsand places that are wetand damp or utensils thathold water are likely to bethe breeding ground formicroorganisms.

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3. Preventive and control measures

Elimination of the source of contamination is fundamentalto the prevention and control of biological hazards.Engineering controls such as improvement of ventilation,partial isolation of the contamination source, installationof negative pressure and separate ventilation and air-conditioning system (e.g. in medical wards for infectious

diseases) and the use of ultravioletlamps can help contain the spreadof contaminants. If the contact withbiological hazards cannot beprevented, the employees must usepersonal protective equipment andadhere strictly to the practice ofpersonal hygiene. The personal

protective equipment includesmasks, gloves, protective

clothing, eye shields, faceshields and shoe covers.

4. Respiratory protection

1. Using the appropriate respiratory protective equipmentis important for the securing an adequate protection frombiological hazards. Common protective equipment includes:

• Surgical masks – Surgical maskgenerally consists of three layers ofnon-woven fabrics. It provides abarrier protection against largerespiratory droplets;

• N95 or higher level respirators – Thistype of respirator f i l ters outparticulates and liquid droplets insmall particle size, therefore providingprotection from inhaling aerosols andmicroorganisms that are airborne.

The selection of particulate respirators should alsoconsider whether the work environment contains oil mists

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Particulate respirators withreplaceable filters

Air-supplying respirator

Powered Air Purifying Respirator (PAPR)

or fumes and the required filtration efficiency necessaryfor the protection level. In general, where there are nooil mists or fumes as in a hospital setting, respirators ofthe N-series with filter efficiency of 95% (Type N-95), 99%(Type N-99) or 99.97% (Type N-100) are suitable. In anenvironment where there are significant amounts of oilmists, then the R-series, R95, R99 or R100 respirators(where R stands for oilresistance), or the P-series, P95, P99 orP 1 0 0 re s p i r a t o r s(where P stands for oilproof) should be used.

• Powered Air Purifying Respirator,PAPR. This type of respirator usesan electric blower to bring the airthrough the filter to the user, makingit more comfortable to wear.

• A i r - s u p p l y i n grespirators. Cleanair is supplied byair compressor orh i g h - p re s s u recylinder through ahose.

2. The type of biological hazard, the nature of work andthe work environment will determine the choice ofrespiratory protective equipment. Adequate training is

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required for using the PAPR and the air-supplyingrespirators to ensure their correct and safe use. It is alsonecessary to follow the manufacturer's recommendationsin the use of these respirators. It is extremely importantthat the respirator should fit the wearer for a good faceseal and the user must perform the seal check to ensurethat the respirator is worn correctly for the requiredprotection.

3. How to use disposable masks

Surgical mask offers a barrier protection from respiratorydroplets. In the use of the masks, it is important to wearthem correctly. When the mask is damp, damaged orsoiled, replace it. A surgical mask in general can be usedfor several hours. If the surface of the mask is touched orthe wearer has coughs, the mask needs to be changedmore often. After use, the mask should be put in a bagor wrapped with paper before disposal. Wash the handsthoroughly afterwards.

4. Points to note about wearing a surgical mask:

• The mask fits snugly over the face;

• The coloured side of the mask faces outwards, withthe metallic strip uppermost ;

• The strings or elastic bands are positioned properlyto keep the mask firmly in place;

• The mask covers the nose, mouth and chin;

• Press the metallic strip on both sides of the bridge ofthe nose to keep the mask snugly over the face;

• Try not to touch the mask once it is worn over theface. If it is necessary to handle the mask, hands mustbe washed before and after touching the mask.

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How to wear a surgical mask

The mask should cover fromthe nose to the chin and fitssnugly over the face.

N O

P Q

• Under normal circumstances, a surgical mask shouldbe changed daily. Replace the mask immediately if itis damaged or soiled.

Put the mask over the face,with the metallic strip atthe top.

Tie the strings behind thehead and neck.

Gently press the metallicstrip over the bridge of thenose.

5. Points to note about wearing a N95 mask:

N95 masks are for use in high-risk medical departmentssuch as casualty department, intensive care units, radiologydepartments (Chest X-Ray examination units) andphysiotherapy departments (chest physiotherapy treatmentunits). Medical personnel that have to take care of high-risk patients or handle high-risk treatment procedures maychoose N95 or higher protection level respirators.

• If required to wear N-95 mask, the face-piece must beof proper fit. Compare the size of different brands tofind a suitable one.

• Follow the instructions of the manufacturer in wearingthe mask;

• To reuse a N95 mask, it should be kept in a paper bagproperly before using it again.

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How to wear a N95 mask

Put on the mask. The headbands should be around thehead and neck.

Note: for the masks with valves, check them according to the instructionof the manufactures.

• If the N95 mask is soiled or damaged, replace itimmediately.

• N95 mask should never be shared with anybody orbrought outside the hospital.

N.B: Improper use of the mask may cause discomfort or reduce itslevel of protection.

N95 masks should not be used by persons:• suffering from respiratory diseases, such as asthma and

emphysema

• having difficulty in breathing or feeling dizzy afterwearing it

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P Q

Choose a small or medium-sized face-piece that fits theface. Pull the head bandsloose. The metallic strip shouldbe uppermost. Pass the handthrough the head bands.

Seal Check:Positive pressure checking –cover the mask lightly with bothhands. Breathe with deliberation.Air should not leak out from theside of the mask.Negative pressure checking –cover the mask lightly with bothhands. Suck in air with deliberation.The mask should depress slightlyinward.

Press the metallic strip onboth sides with the forefingersand middle fingers of bothhands.

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biological hazardrubbish bag

5. Protective clothing

• Protective clothing includesprotective coverall (withattached hood), gown, apron,head and shoe covers;

• Protective clothing should bewaterproof or impervious toliquids to protect the bodyfrom contamination by blood,droplets or other body fluidsa n d p r e v e n t t h e s econtaminants from gettinginto the body through openwounds or contaminating theworker's own clothing, thusreducing the chance ofspreading of pathogen andcross-infection;

• Protective clothing is disposable in most cases thoughsome can be reused after sterilization;

• Standard protective clothing should be chosen (forexample, EU EN 340);

• Protective clothing should fit the wearer and shouldnot hamper movement;

• Protective clothing should be checked before use andreplaced if damaged;

• Biologically contaminatedprotective clothing shouldbe disposed of in speciallydesigned rubbish bagmarked with "biologicalhazard" warning and label.Seal the bag and place itin designated location forspecial disposal;

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• How to put on protective clothing:Take up the gown with the back facing the wearer.Slip the arms through the sleeves first and tie the collarstring behind the neck. Then tie the string around thewaist;

• How to take off protective clothing:Loosen the collar string. Slip off the sleeves on bothsides and the upper part of the gown. Turn the gowninside out. Roll it outward and dispose.

6. Goggles/Face shields

• Safety goggles/glasses and face shields can protectthe eyes from contacting pathogen-carrying blood,droplets or other body fluids which may then enterthe body through the mucosa;

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• Standard goggles should be chosen (for example, EUEN 166; U.S. ANSI Z87.1-1989);

• Glasses without side shields can onlyprotect the front from liquid splash ;

• Goggles fit the face snugly andtherefore are better than glasses ineye protection;

• If necessary, face shield should beused to protect the whole face;

• Both face shields and goggles/glasses should becleaned with liquid soap regularly. If contaminatedby blood, they should be soaked in 1:49 diluted liquidbleach and then rinsed with clean water. Place themin plastic bags after wiping dry and store them in acabinet;

• Check them regularly. Replace them if out of shape,cracked, scratched or fogged;

• How to put on goggles:Hold the goggles withone hand and placethem in front of theeyes. Put the headband around the headand adjust to fit.

• How to take off thegoggles:Hold the goggles lightlyand slip off the headband. Keep the gogglesin a proper place orsterilize them.

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• How to put on a face shield:Before use, assemble the face shield according toinstructions given by the manufacturer. The way to puton and take off a face shield is similar to that of goggles.

7. Gloves

• Gloves protect the hands from contacting blood,droplets, body fluids and other body tissue of theinfected, or pathogen-contaminated objects and canavoid infection when touching theeyes, mouth or nose afterwards.Gloves can also protect openwounds from contamination bypathogen;

• Most gloves are disposable after use;

• Standard gloves should be chosen (for examples, EUEN 374; U.S. ASTM F1670, ASTM F1671);

• Check whether the material used for the gloves isresistant to chemicals. Ask for details from the glovessuppliers;

• Gloves should fit the hands snugly but they shouldnot hamper movement or affect sensibility;

• Keep the nails short to avoid piercing the gloves;

• Two pairs of gloves might be worn in handling highlyhazardous substances;

• Wash hands thoroughly before and after use;

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An inflated glove means thatair is trapped inside andthere is no puncture.

Fold the open end of theglove and roll it up to trapair inside.

• Check if there is any puncture before use. To do so,roll up the open end of the glove to see if it can trapair inside (see diagrams below). A punctured gloveshould be replaced immediately. (N.B: Do not blowthe glove directly to avoid direct contact of the mouthand nose with the glove.);

• Contaminated gloves should be disposed of in specialrubbish bag marked with "Biological hazard" warningand label. Fasten the bag and place it in a designatedlocation for special disposal;

• How to put on gloves: putthem on before handling anyblood or objects with potentialbiological hazards. Wear apair that fits the hands andappropriate for the job;

• How to take off gloves: change or take off the glovesevery time after contacting a patient or handlinglaboratory specimens. Disposable gloves should neverbe reused. To take off the gloves, grab the rim of theleft glove with the right hand and then pull it off awayfrom the body to turn it inside out. Then use the insideof the left glove to cover the right glove and peel it

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8. Shoe covers

• Shoe covers prevent pathogens from being carriedoutside the workplace;

• Shoe covers are usually disposable after use;

• Boot covers offer furtherprotection. Cover the bootswith the trousers of protectivec l o t h i n g t o p r e v e n tcontaminants from getting intothe boots;

• Shoe covers should be waterresistant and skid proof;

• The size should fit so as not to hamper movement.

To ensure their protectiveness, all personal protectiveequipment requires correct selection and use, as well asproper maintenance and storage. Re-useable protectiveequipment should be cleaned and sterilized thoroughlybefore they are used again. Damaged items should bereplaced immediately.

When using the complete set of protective equipment,medical personnel should follow strictly hospitalguidelines on infection control. Other general frontlineworkers such as cleaning staff should refer to the followingorder in putting on protective equipment. However, this

off gently. Dispose the gloves. In this way, there willbe no skin contact with the outside of the gloves.

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order has to be adjusted according to the workenvironment to prevent cross-contamination.

The sequence to put on a general full set of protectiveequipment:

The sequence to take off protective equipment:

The items taken off should be disposed of in specialrubbish bag marked with "Biological hazard" warning andlabel. Fasten the bag and place it in a designated locationfor special disposal.

9. Sterilization

Sterilization is the process using ultra heat or highpressure to eliminate bacteria, or using biocide toeliminate microorganisms, including spores in bacteria.A complete sterilization process should includedisinfecting the contaminated premises and thoroughcleaning of any residual toxic substances, to ensure thatemployees would not be harmed through exposure inthe risk area. Effective sterilization depends on the strainand amount of microorganisms, the level of organicmaterial present, the properties of the organisms to beeliminated, and the duration, temperature andconcentration of the sterilizing agent. Sterilization mustbe carried out by following strictly safety guidelines andtaking personal protection to safeguard the health andsafety of employees. There are many kinds of sterilizingand antiseptic agents, themost common ones beingliquid bleach and rubbingalcohol. Hands must bewashed thoroughly aftertaking off any personalprotective equipment.

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Before work

After workDuring work

10. Personal hygiene

Washing hands with liquidsoap is the simplest and mostbas ic method to avoidinfection. However, it is oftenneglected. Wash handsbefore and after work. Alsowash hands immediatelybefore and after wearingprotective clothing, uniformsor gloves to reduce thepossibility of infection.

11. Conclusion

Biological hazards can kill. Or they may cause discomfortand affect the health and performance of employees atthe very least. We have to be vigilant in preventing andcontrolling biological hazards to make the workenvironment a safer and healthier place.

Copyright 2003 Occupational Safety & Health Council 5/03 (01)

9 789629 681807

ISBN 962-968-180-3