Understanding the practicalities of using

gas detectors in confined spaces

BOHS

Wednesday 28th February 2018

SCI Society Of Chemical Industry, Knightsbridge, London

Leigh Greenham BSc CEng MIET Electromagnolia Ltd & CoGDEM

Today’s presentation

• legislation and guidance

• choice of instruments

• differences between ‘personal’ and ‘portable’

gas detectors

• new developments

• technicalities

• further guidance

CoGDEM

• Council of Gas Detection and Environmental Monitoring

• Founded in 1974, around 60 member companies

• Members are manufacturers and service providers in the field

of gas detection

• HSE/HSL are guest members

• Protecting everything from the smallest bedsit to the largest

offshore oil or gas platform

• Key role in writing standards

• co-author of the latest version of BOHS TG15 (Direct Reading

Devices for Airborne Chemical Contaminants)

• freephone helpline for users – 0800 1694 457

Standards, regulations and guidance

• HSW Act

• COSHH

• EH40

• Confined Space Regulations

• ATEX (hazardous area – ignition protection)

• Gas Detector Performance standards

• BOHS TG 15 (includes data on EN 689 and EN 482)

• industry-specific guidance (e.g. CoGDEM Guide

to Gas Detection, BCGA GN11)

EH 40

Oct 2007,

new limits for:

• bromine

• pentane

• phosphine

• chlorine

• toluene

But where are?

• NO

• NO2

• SO2

Makes life

difficult for

instrument

manufacturers

and users

21 Aug 2018 ?

potential new

lower limits for:

NO (2 ppm only)

NO2 (0.5 & 1 ppm)

SO2 (0.5 & 1 ppm)

CO (20 & 100 ppm)

HCN (0.9 & 4.5 ppm)

Consultation

closed on 2/2/18

Choice of gas detection instruments

• Personal

• Portable

• Transportable

• Fixed

Personal gas detectors

Typically:-

• small, can be lapel-mounted

• single toxic gas or oxygen

• one or two year life

• sealed for life battery

• limited display

• no pump option

• limited datalogging

• inexpensive, starting ~£90

Personal gas detectors

But also:-

• no servicing

• no calibration

• no battery charging

Does that mean no testing?

Personal gas detectors

BS EN 60079-29-2 and BS EN 45544 states

that for any portable flammable gas, oxygen or

toxic gas detection instrument:-

“Inspection and functional checks are intended to verify

that the equipment is in a working state. It is

recommended that they are done by personnel actually

operating the equipment, and is strongly recommended

that they are performed before each day of use,

particularly if the equipment has catalytic,

electrochemical, or semiconductor sensors and is being

used under arduous conditions.”

Portable gas detectors

Diffusion vs sampling

• appropriateness

• may avoid need for confined space entry

• drop-line or sampling hose?

• manual aspiration or pumped?

Types of readings

• spot check – snapshot (consider response time)

• trend analysis (approaching an alarm condition)

• time weighted average (to check compliance)

• peak monitoring (risk assessment)

Calibration vs gas-testing

• frequency

• need for traceability

• accuracy of calibration gas or test gas

• training and competency

• automated docking stations

Development of portable/personal

gas detectors

• improvements in instrument performance

• PID toxic gas sensing techniques

• wider range of toxic gases detectable

• infrared sensors for flammable gas & CO2

• HSW Act and CSE often defines a market need

& drives the need for sensor development

• longer battery life

• comms capabilities

PID basics

• correction factor tables for over 350 compounds

• instruments often have built-in corrections for:

benzene, toluene, ethylene, acetone, styrene, isopropanol, ethyl acetate

• typically calibrated to 100 ppm isobutylene

What type of instrument is this?

What type of instrument is this?

Trick question!

Sensor Failure Rate

Bum

p T

est

Daily

Monthly

Monitor

Single sensor inst. Dual sensor inst

1 in 1,265*

1 in 286*

1 in 116,257*

1 in 21,320*

Failure

92 times

less

likely

Failure

74 times

less

likely

DualSense Technology

Increases Gas Detector Reliability

*Analysis is based on over 2.2 million bump tests and

over 100,000 unique sensors logged in iNet.

V16:9

© Copyright All Rights Reserved Crowcon Detection Instruments Ltd.

+ve Safety™

Data & Event Logging

Visual Alarm Bars

Vibrate Alarm

External Filter Plate

Clear screen with 180 flip

for easy viewing

One Button Operation

Integral Rubber Boot

Extremely rugged

TWA Resume* prevents

overexposure to toxic gases

18 Hour Run Time

5.5 hour recharge

95 dB Alarm

IP 65/67

Cradle Charger Multi Region

Power Supply

T4 Features

Light weight (280g) * Patent pending UK patent application number 1501699.1

4 Sensors for 4 Gases

(~£400)

V16:9

© Copyright All Rights Reserved Crowcon Detection Instruments Ltd.

Gas-Pro Features Gas-Pro Overview

• Measure up to 5 gases

• Optional pump up to 30 metre (100 feet) sampling

• Pre-Entry Check function

• +ve Safety for full unit compliance

• Full data/event logging for record keeping

• User definable, set up to site requirements

• Robust unit for harsh environments IP65 & IP67*

• One button for ease of use

• Top mount display for quick decision making

• Multiple charging options

• Easy test solutions for bump and calibration

*IP66 PID Unit

23

(~£1250 for 5-gas version with PID)

V16:9

© Copyright All Rights Reserved Crowcon Detection Instruments Ltd.

Gas-Pro Overview Gas-Pro Options

• Oxygen

• Toxic (Electrochemical)

• Flammable (Pellistor)

• Flammable (IR)

• Carbon dioxide (IR)

• VOC (PID)

• Flammable Calibrations:

24

BLACKLINE SAFETY G7 Works out of the box, 3G cellular and

satellite

Gas detection, falls, no-motion, check-

ins, SOS

Real-time alerting for instant awareness

Two-way voice and text messaging

Mass notification to individuals or

groups

Live evacuation management

Satisfies needs of lone workers

Monitored via easy web-based software

Emergency response management

tools

LOCATION TECHNOLOGY

Delivering help to an employee

requires accurate knowledge of

his/her location

Multiple location technologies:

Assisted-GPS for outdoor location

Location beacons for affordable

indoor locations

Often, Google Maps alone isn’t

enough to show an employee’s

location

Multi-level floor plans, site plans

BLACKLINE SAFETY G7

• G7 Hardware - £355.00 per device

• Singles Gas - £36.00 per year (any

sensor that is available)

• Quad Gas - £108.00 per year (any

sensor that is available)

• Service packages - Self Monitored with

2-way voice £252.00 per year, per

device or Blackline monitored with 2-

way voice £384.00 per year per, per

device

Typical examples - Draeger

Typical examples - RAE

Typical examples - Honeywell

Typical examples - GMI

Typical examples - GfG

Typical examples - Biosystems

Typical examples - ISC

The CoGDEM Guide to Gas Detection

Selection of equipment

• Type of gas hazard – flammable, toxic, oxygen or

combination

• Personnel or plant protection

• Fixed, portable or transportable

• Sensor technology

• Detection range and alarm points

Standards

• Hazardous Areas (ATEX Directive, IECEx)

• Performance standards

• Functional Safety

• CE Marking

• Health & Safety Regulations

• Confined Spaces

Installation & Training

• Professional installation of fixed equipment

• Location of gas detectors or sampling points

• Training for user, maintainer, management

• Occasional user (e.g. contractor)

Calibration & Bump-testing

• Planned maintenance

• Regular calibration

• More regular bump-testing

• Know your test-gas supplier

Other book inclusions

• Chemistry of gases, units of measurement etc.

• Reference section

• Non-industrial gas hazards

• Data about CoGDEM

Slide title