©EnviroDerm Services 2016 1

Chris Packham EnviroDerm Services

©EnviroDerm Services 2016 2

Assessing Chemical Hazards for Skin Exposure Risk Assessment

If we are to ensure a valid risk assessment for skin exposure to chemicals it is essential that this is based on the real hazard present when the task is carried out.

In a very large number of cases the safety data sheet will not provide us with this information.

There is an enormous number of chemicals that in contact with the skin can cause damage, but that have never been assigned a relevant hazard statement.

4350

©EnviroDerm Services 2016 3

Assessing Chemical Hazards for Skin Exposure Risk Assessment

It is also highly probable that the ‘Exposure Scenario’ will also not be a reliable source of hazard information.

We generally purchase chemicals to use for a particular task. In carrying out the task we may alter the properties of the chemical – and thus alter the hazard that is present during the task and that should form the basis for our risk assessment.

A study by the European Chemicals Agency (ECHA), the organisation responsible for REACH, found that of 1,181 companies they inspected in 29 countries, mostly ‘downstream users’, i.e. formulators, regarding compliance with REACH, 52% were producing safety data sheets described in the study as ‘deficient’. ECHA – REACH-EN-FORCE2

©EnviroDerm Services 2016 4

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Contamination, e.g. in cleaning chemicals, solvents used for degreasing items, etc. Reaction between two or more chemicals, e.g. epoxy resins used in glass fibre mouldings, two pack paints Processes that change the properties of the chemical, e.g. vulcanising rubber

©EnviroDerm Services 2016 5

Assessing Chemical Hazards for Skin Exposure Risk Assessment

“Major changes were found in which added chemicals were consumed and new ones produced.” – from Chemical changes in rubber allergens during vulcanization” - Bergendorff O, Persson C, Lüdke A, Hansson C, Contact Dermatitis, 2007, 57, 152-157

“Moreover, due to high pressures and temperatures during curing more (unknown) chemical substances are being formed and released. This complex exposure profile does not only differ between rubber factories but also in time due to variations in production and control process requirements for different products and variation in work practice.” – Roel Vermeulen, doctoral thesis, Utrecht University

©EnviroDerm Services 2016 6

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Contamination, e.g. in cleaning chemicals, solvents used for degreasing items, etc. Reaction between two or more chemicals, e.g. epoxy resins used in glass fibre mouldings, two pack paints Processes that change the properties of the chemical, e.g. vulcanising rubber Oxidisation, changing the chemicals to introduce sensitisers

©EnviroDerm Services 2016 7

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Oil from peel of citrus fruit d-limonene (terpene)

Environmentally preferable to petroleum based products?

Potent (photo)sensitisers

Oxidisation

C10H16++

Oxygen

Excellent degreasant.

Skin irritant (due to skin defatting), but not sensitiser

©EnviroDerm Services 2016 8

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Contamination, e.g. in cleaning chemicals, solvents used for degreasing items, etc. Reaction between two or more chemicals, e.g. epoxy resins used in glass fibre mouldings, two pack paints Processes that change the properties of the chemical, e.g. vulcanising rubber Oxidisation, changing the chemicals to introduce sensitisers Heating can change the properties, e.g. solder flux Metabolisation within the skin, e.g. methanol may metabolised to release formaldehyde as a metabolite Changes in chemicals over time, e.g. biocides that are formaldehyde releasers Physical changes, such as leaching of metals into metalworking fluid, grinding causing fine dust that can settle on the skin

and, of course, combinations of these effects!

©EnviroDerm Services 2016 9

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Does dilution reduce the hazard? In this study Drexler and his colleagues found that 2-Butoxyethanol, when diluted with water, penetrates the skin in considerably greater volume and speed that when neat.

“In vitro Untersuchungen zur Hautpenetration von 2-Butoxyethanol und seinen wässrigen Verdünnungen” – poster at occupational medicine conference in Innsbruck, Austria, 2004

04/05/2016 ©EnviroDerm Services 2012/2015 10

Allergic contact dermatitis to Tetraglycidyl Methylenedianiline (TGMDA) in an aerospace plant

They had a number of people who had been working with this material for some years. Now they had received a claim for compensation from a worker stating that she was suffering with allergic contact dermatitis from working with this material.

Assessing Chemical Hazards for Skin Exposure Risk Assessment

04/05/2016 ©EnviroDerm Services 2012/2015 11

Safety Data Sheet for pre-impregnated carbon fibre sheet:

Constituent Classification Content

Dapsone Xn, R22 10-30%

Dichloromethane Xn, R40, Carc3 0-2%

Tetraglycidyl Methylene Dianiline (TGMDA)

Xn, N, R21/22, R43, R51/53, R68 Mut3

60-100%

R21- Harmful in contact with skin R22 - Harmful if swallowed R40 - Possible risk of irreversible

effects R43 - May cause sensitisation by

skin contact

R51 - Toxic to aquatic organisms

R53 - May cause long term adverse effects

R68 - Possible risk of irreversible effects

Assessing Chemical Hazards for Skin Exposure Risk Assessment

04/05/2016 ©EnviroDerm Services 2012/2015 12

Assessing Chemical Hazards for Skin Exposure Risk Assessment

04/05/2016 ©EnviroDerm Services 2012/2015 13

‘Dyneema’ gloves that had been worn for 4 days handling this material were analysed by the U.K. Health and Safety Laboratory.

Contamination by TGMDA after 4 days was so low that it could be excluded as a significant risk for skin reactions.

However, in another process the same mat was softened with a solvent. Here the TGMDA was bioavailable. However, due to the solvent, adequate controls were in place.

Same chemical – but very different hazards!

Assessing Chemical Hazards for Skin Exposure Risk Assessment

©EnviroDerm Services 2016 14

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Select task

Define task

Identify chemicals used

Determine hazards of chemicals as used

Assess risk and severity of damage to health

Next task

Check effectiveness

Specialist support!

Chemical hazard data from suppliers and from other

sources

Identify exposure

Uncertain Unacceptable

Introduce controls

Acceptable

©EnviroDerm Services 2016 15

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Select task

Define task

Identify chemicals used

Determine hazards of chemicals as used

Assess risk and severity of damage to health

Next task

Check effectiveness

Specialist support!

Chemical hazard data from suppliers and from other

sources

Identify exposure

Uncertain Unacceptable

Introduce controls

Acceptable

I could argue that the most difficult part of any risk assessment for skin exposure is

determining the real hazard!

©EnviroDerm Services 2016 16

Assessing Chemical Hazards for Skin Exposure Risk Assessment

Questions

. . . and if you have thoughts on how we might find a solution to this problem I would welcome

these.

?