CONFINED SPACE VENTILATION ENHANCEMENT

HASZELINA HASSAN

INDUSTRIAL HYGIENIST PRINCIPAL

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PRESENTATION OUTLINE

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1. Confined Space Risks

2. Rationale Behind the Enhancement

3. Common Factors Leading to Incidents

4. Enhancement in Existing Practices

5. Conclusion

• Characteristics

• Work Activities

• Hazards

CONFINED SPACE

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Risks of Working in a Confined Space

RATIONALE BEHIND THE ENHANCEMENT

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TRIGGERING POINT

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Atmospheric, 373, 56%

Loose materials, 227,

34%

Others, 70, 10%

TYPES OF HAZARDS RESULTING IN670 CONFINED SPACE DEATHS

Source : OSH online 2018-US NIOSH

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1

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3

4

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

Nu

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of

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Year

Company Confined Space Incidents

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Risk Assessments

• Incomprehensive JHA e.g. too generic

• Failed to anticipate / recognize hazards

Ventilation Plan

• Insufficient planning

• Substandard implementation

Communication

• Understanding of SSOW e.g. PTW, EIS, ERP

• Effectiveness of hazard communication e.g. toolbox, safety briefing

Workers Factors

CompetencyFatigue causing errors

• Learning from incident root causes and plant turn around activities.

COMMON FACTORS LEADING TO INCIDENTS

• Multiple engagements with plant personnel including contractors in charge, business sectors and corporate group to obtain optimum ventilation arrangement.

COLLABORATION ACROSS MULTIPLE DISCIPLINES

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ISSUES AND CHALLENGES

Determination of optimum flow rate based on multiple contaminants produced

Simplified calculation method for user.

Atmospheric testing for contaminants.

Efficient distribution of fresh air supply and exhaust contaminated air.

Arrangement of ventilation equipment.

VENTILATION ENHANCEMENT

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Atmospheric testing protocol.

Minimum requirements in ventilation plan inclusive of target flow rate based on type, number of contaminants and byproduct from activities in CS.

Ventilation equipment configuration.

ATMOSPHERIC TESTING

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1. Fit-for-purpose sampling equipment (e.g., type, calibration)

2. Contaminants to be sampled based on risk assessment (e.g., HRA / CHRA)

3. Sampling practices (i.e. sequence of testing, sampling points, duration of sampling)

4. Testing must done prior to each entry and after breaks longer than 30 mins

Test the atmosphere at all levels of the confined space; good air near the opening doesn’t mean good air at the bottom!!

VENTILATION PLAN MINIMUM REQUIREMENTS

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• Type of activities.

• Type of mechanical ventilation

• Atmosphere test results.

• Required ventilation rates

(m3/min)

• Number of fans

• Type of gas detectors and

quantity

Specific for each confined space entry and task based.

Equipment drawing which includes:

✓ Type of confined space equipment

✓ Size and volume of confined space

✓ Number and position of manholes, inlets, outlets and any other openings.

✓ Ducting layout✓ Location of fans.

VENTILATION WORK PROCESS

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(m3/min)

Duration depends on:

• Initial concentration of

the contaminants (ppm)

• Capacity of the fan

(blower or extractor)

used (m3/min)

• Volume of confined

space (m3)

Pre- entry ventilation (min)

Required ventilation rate is determined by:

• Rate of contaminants

generation (m3/min)

• Target concentration

(ppm)

• Safety factors

Ventilation During Entry (m3/min)

AUTOMATE TARGET FLOWRATE CALCULATION

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(m3/min)

Calculation is automate to aids personnel at site in determining the estimated safe target ventilation rate

VENTILATION EQUIPMENT CONFIGURATION

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OVERVIEW ON GOOD AND SUBSTANDARD PRACTICES

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The enhancement was well accepted by personnel at sites, new ways in setting the target flow rate based on prediction of multiple contaminants volume and arrangement of ventilation equipment.

This improvement to the existing practices and standards were successfully implemented across PETRONAS facilities.

CONCLUSION

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Acknowledgements

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PETRONAS Industrial Hygienist team

Downstream Turnaround Teams

Downstream Strategic Intervention Team

PETRONAS Plant Personnel

PETRONAS Contractors

PETRONAS GHSE

Thanks and Questions

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