DSEAR for Ammonia Refrigeration Systems

Dr Dermot Cotter

Star Technical Solutions

What is DSEAR?

The acronym for:

The Dangerous Substance and Explosive Atmosphere

Regulations 2002

It is a Statutory Instrument 2002 No. 2776

Health and Safety

Purpose of DSEAR (For Ammonia System)?

Eliminate or Reduction of Risks from Dangerous Substances

For Ammonia Refrigeration System • This Means Eliminate or Reduction of Risk of an Ammonia

Explosion • The Hazardous Zones to be Classified (EN 60079-10-1) • If there is an Ammonia Release, there is a Practiced

Emergency Response Plan in Place

Other Key Legislation for Ammonia System

• The Management of Health and Safety at Work

Regulations 1999 • The Pressure System Safety Regulations 2000 These Regulations Require Risk Assessments to be Carried

Out that will identify if the Ammonia Refrigeration System is Safe to Operate

The Risk Assessment would Identify the Toxicity Risks of Using Ammonia

Knowledge and Experience Required

A Clear Understanding of Good practice: • EN378 Refrigeration Systems and Heat Pumps – Safety

and Environmental Requirements Parts 1 – 4. • EN 60079 Explosive Atmospheres – All parts • PM81 – Due to be Published Soon

Experience: • Ammonia Vessel and Piping Systems • Understanding Ammonia in the Event of a Release which

Includes Dispersion Modelling • Ammonia Safety Systems • ATEX Equipment

Knowledge form The IIAR

Knowledge form The IIAR

Ammonia Regulatory Compliance – WHY NOW?

STS Experience of Site Compliance to Regulations

Explosive Risk - Non Compliance

• Gas Detection System – Not Calibrated • Gas Detection System – Incorrect Sensors, Location &

Alarm Settings • Gas Detection System – Does not Remove Power to

Non ATEX Equipment or Not Tested • Door Not Sealed Between Machinery and Electrical

room – Explosive Atmosphere in Electrical Room • Machinery Room Extract Fans or Electrical Room

Pressurisation – Not Functioning • Emergency Extract Fans – Not ATEX • Extract Air from Compressor Area Only – Surge Drums? • Roof Voids – No Extract Fans or No Air Movement Over

Ammonia Valve Stations • Fire Alarm System or Emergency Lighting – Not ATEX • The ATEX Equipment – Not Checked Every 3 Years

Toxic Risk - Non Compliance

• Extract Fans – At Low Level • Relief Valves Vents – Pointing Downwards • Relief Valve Vents – Pointing Horizontal by Condensers • Emergency Plan – Evacuate Persons to Yard Area • AHU Air Intakes – On an Ammonia Release Air is Drawn

into Buildings & Roof Voids • No Second Escape Route – From Machinery Rooms and

Condenser Areas • Electrical Room Pressurisation Fan Draws in Toxic gas in

the Event of an Ammonia Release in Machinery Room due to location of the Machinery Room Extract Fan

Other - Non Compliance

• No mention of Ammonia During Site Inductions • Permit to Work Systems Inadequate • No/ Poor Quality Ammonia Release Response Plan • Ammonia Release Response Plan Not Tested • No Written Scheme of Examinations (PSSR 2000) • Written Scheme of Examination Not Adequate – No Site

or Piping Inspections • No Catchment Around Ammonia Liquid Vessels (EN378) • No Emergency Shower or it is Not Tepid • Location of Emergency Shower Makes it Unusable • No Eye Wash Facilities • Lack of Labelling of Ammonia Areas

STS View for Compliance with Regulations

• Pressure Systems Safety Regulations 2000 – Pressure Envelope is Safe

• The Dangerous Substance and Explosive Atmosphere

Regulations 2002 – Deals with Explosive Risks

• The Management of Health and Safety at Work Regulations 1999 – Deals with Toxicity Risks

STS Recommends that All Sites have an Ammonia Risk / Hazard Assessment and It is Reviewed Every 3 Years