the role of biological monitoring in managing occupational skin exposure to isocyanates · 2020. 3....

Health and SafetyExecutive

© Crown Copyright, HSE 2019

The role of biologicalmonitoring in managingoccupational skin exposureto isocyanates

16 September 2019

Kate Jones


What is Biological Monitoring?Assessment of overall systemic exposure to

chemicals by measurement of the chemicals or theirbreakdown products in

blood and breathurine


Dermal-specific techniques• Interception

– Patches, gloves, suits• Removal

– Hand-washing, tape-stripping• Visualisation

• No simple measure• No agreed standard approach


Disentangling exposures

Airborneconcentration

BM value

Dermal absorption ?

RPE ?


Skin Structure

E P ID E R M IS

D E R M IS

S U B C U T A N E O U S

V A S C U L A RS U P P L Y

S tra tu mc o rn e u m

S tra tu m b a s a le

h a ir fo ll ic le

s e b a c e o u s g la n d

s w e a t g la n d

h a ir

p o re

n e rv e e n d in g

P a c in ia nc o rp u s c le

M e is s n e rsc o rp u s c le

F A T

[J e w e ll C .J . a n d W ill ia m s F . M . N e w c a s t le U n iv e rs ity , w it h p e r m is io n ]


Delayed absorption/excretionUr

inary

excr

etion

Time from start of dose (h)


Reservoir effectF ifte e n m in u te d e rm a l e x p o s u re

0

5

1 0

1 5

2 0

2 5

0 2 4 6 8 1 0 1 2 1 4

T im e h o u rs

Urinar

y 5-HN

MP D e rm a lE x p o s u re


Is dermal absorption significant?

Urinary 5-HNMP after inhalation (8h, 10mg/m3) or dermal (1 hand, 15min, 15%) exposure to NMP

10 20 30 40 50 60-5

0

5

10

15

20

25InhalationDermal

Time (hours)

Urina

ry 5-

HNMP

Akrill et al (2002). Toxicol. Lett. 265 - 269


Isocyanates

• Primarily considered an inhalation hazard, causingrespiratory sensitisation

• However, also cause skin sensitisation and evidenceto show that skin exposure can induce respiratorysensitisation

• Is there evidence to show skin uptake of isocyanates?


Laying floor screed


Industrial Flooring Panels


Intervention – glove type

Glove Type

MDA

inur

ine(µm

ol/mo

lcrea

tinine

)

Leather

Polyester0

2

4

6

8


Longitudinal monitoring

07/09/2015

03/11/2015

17/05/2016

06/06/2016

19/09/2016

06/02/20170

2

4

6

8MD

Ain

urine

(µm

ol/m

olcr

eatin

ine)

BMGV


Individual worker exposure patterns

07/09/2015

03/11/2015

17/05/2016

06/06/2016

19/09/2016

06/02/20170

2

4

6


BM for skin exposure to isocyanates

• Evidence that for MDI (low volatility, low aerosol processes)skin uptake can occur

• Can result in significant body burden compared to UK BMGV

• Tasks may need to be redesigned for best intervention asPPE requires ongoing management

• Even when problem ‘solved’, monitoring is required toreinforce behaviours.


Thanks for listening

Any questions?

[email protected]

the role of biological monitoring in managing occupational skin exposure to isocyanates · 2020. 3....

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