BCC 6-01

April 2006

Carbon Monoxide

Vulnerable age

Persons aged 65 years or over

Related hazards

Fire

Gas fire in front reception room

(right)

DESCRIPTION OF HAZARDS

HHSRS Operating Guidance:

February 2006

Multiple locations

Yes

No

Secondary hazards

Yes

No

Back-boiler and fire front in rear

reception room (left)

Dwelling: Two storey, mid terraced, pre-1920 house

Background: This is a traditional two storey house built around 1908. It comprises two rooms, a kitchen and

bathroom on the ground floor and three rooms on the first floor. Windows are 10 year old pvc-u double glazed units with

no trickle ventilators. Heating is by a gas-fired central heating installation from an open-flued back-boiler with fire in the

ground floor rear room and radiators to each of the rooms with the exception of the ground floor front room. This has an

open-flued gas appliance which is poorly sealed into the fireplace opening. The installation is about 40 years old and

there has been no servicing in the last 5 years. There is an air brick in the external wall of the ground floor rear room

that has become partially blocked with general debris and does not meet current background ventilation requirements.

There is no background ventilation provided in ground floor front room. There is no evidence of sooting or staining

around either of the appliances although there is flame discolouration and flicker to the back-boiler and fire. There are

no CO detectors in the dwelling.

LIST OF RELEVANT MATTERS

LIKELIHOOD & HARM

a

Flueless appliances

-

Key

3

Seriously defective

b

Disrepair to appliance

1

2

Defective

c

Inadequate ventilation

2

1

Not satisfactory

d

Disrepair to ventilation

2

-

Satisfactory/NA

e

State of flues

-

f

Disrepair to flues

-

g

Flue outlet siting

-

h

Extractor fans

-

I

Ventilation lobby

-

j

Carbon monoxide detectors

3

Score: 273

H

I

J

G

%

Av: Pre 1920 Non-HMO: 0.0

0.1

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 0.0

RATING

A

B

C

D

E

F

Average likelihood and health outcomes for persons aged 65 years and over, 1997-1999

NEW RATING

Av: Nos

Score: 1

H

I

J

G

BCC 6-01

April 2006

HEALTH AND SAFETY RATING SYSTEM SCORES

Low

High

1 in

LIKELIHOOD

Av: Pre 1920 Non-HMO: 1,150

< 4200 2400 1300 750 420 240 130

75

42

24

13

7.5

4

2.5

1.5 >

Justification

The disrepair to the fire in one of the reception rooms, the lack of ventilation in the ground floor front room and

inadequate ventilation in the ground floor rear room will increase the likelihood of a harmful occurrence. The heating

system, although operational has not been serviced regularly and there is evidence of incomplete combustion from the

fire and the back boiler which will be used frequently therefore increasing the likelihood substantially. The lack of CO

detectors will also mean that occupiers will be unaware if CO levels were elevated.

OUTCOMES

Class I

Class II

RATING SCORES AFTER IMPROVEMENT

IMPROVE

Likelihood to

1 in 1,000

Outcomes to

0.0

0.0

2.2 97.8

%

Justification

Servicing and repairing the appliances and providing adequate ventilation coupled with the provision of CO detectors

would reduce the likelihood of harm and the spread of harms to average for the age and type of property.

Av: 1

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 2.0

Class III

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Class IV

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

0.1

2.2

Av: 98.0

97.6

Justification

The estimated average percentage of Class I harm in the in the Operating Guidance is acknowledged to be very

probably an under estimate, and there is uncertainty as to numbers affected by sub-acute levels of CO. Exposure to CO

in the main living room over a prolonged period is likely to lead to an increased proportion of extreme and severe

outcomes for the vulnerable age group.

Av: Pre 1920 Non-HMO: 1

A

B

C

D

E

F

10