BIOCIDES

Vulnerable group

Related hazards

Front elevation of flat

All ages

VOCs

HHSRS VERSION 2

SEPTEMBER 2004

HHSRS VERSION 2

Multiple locations

Yes

No

Secondary hazards

Yes

No

Rear elevation of flat

A)

Insecticide: This is a conversion of a former HMO into three self-contained dwellings. During the

conversion works, woodworm infestation to first floor landing was discovered. On further

investigation, it was clear that there was a live woodworm infestation affecting timber to the whole of

the first floor and to most of the ground to first floor staircase. All the timber to the first floor and the

staircase was stripped out and renewed with timber treated with insecticide to prevent re-infestation.

The remaining timber to the dwelling, including the ground floor floor, the first floor ceiling and the

roof timbers were thoroughly treated. Following the timber treatment, the windows in the treated

rooms were left open for only a limited period, being subject to the presence of the builders and

reasonable weather conditions. However, within a week of the completion of the conversion, less

than two months after the completion of the timber treatment, all the flats were occupied.

LIST OF RELEVANT MATTERS

LIKELIHOOD & OUTCOMES

A

a

Use of biocides

3

b

Misuse - re. Instructions etc

3

A

-

Seriously defective

Defective

Not satisfactory

Satisfactory/NA

Front of block during conversion

Rear of block during conversion

DESCRIPTION OF HAZARDS

Dwelling: First floor flat in 1900 detached house.

# Secondary hazards

-

None

Key

3

2

1

-

A B C D E F G H

I

J

Average likelihood, outcomes and HHSRS score for biocides for all persons in pre 1920

HMOs.

HHSRS VERSION 2

SEPTEMBER 2004

HEALTH AND SAFETY RATING SYSTEM SCORES

Pre 1920 Non s.c. Flat

1 in

18

LIKELIHOOD

Low

High

Average: 513,333

Example

18

< 4200 2400 1300 750 420 240 130

75

42

24

13

7.5

4

2.5

1.5 >

Justification

OUTCOMES

Class I

Class II

Class III

Class IV

Justification

RATING

All the new timber and all the remaining old timber have been treated with biocides. Until

fumes have fully dispersed, the occupants of each flat will be at risk, particularly those in

the first floor flats. Although the fumes emitted are likely to reduce to safe levels after

two to three months, until then, the occupants are exposed to dangerous levels.

%

Average: 0.0

0.0

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 0.0

0.0

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 9.1

31.6

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

Av: 90.9

68.4

Score:

<1

0.0

0.0

31.6

68.4

< 0.05 0.15 0.3

0.7

1.5

3

7

15

26

38 >

As all rooms have been treated, including bedrooms, occupants cannot escape the

fumes, and the likelihood of harm is increased by the prolonged exposure.

Average: <1

I

J

Example

A B C D E F G H

564

Score

RATING SCORES AFTER IMPROVEMENT

IMPROVE

Justification

NEW RATING

Av: Nos

Likelihood to

1 in 5,600

Outcomes to

0

0

10.0 90.0 %

The occupants should be rehoused temporarily and each dwelling thoroughly ventilated

before the occupants move back. To have reduced the likelihood of the hazard

occurring, the use of any biocide should have been limited or, if possible, avoided.

Where used, all treated areas should have been well ventilated. New timber need not

have been treated.

Improved