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SKerr  
#1 Posted : 18 January 2020 22:55:22(UTC)
Rank: New forum user
SKerr

i have been carrying out a COSHH assessment and the MSDS states that this is a respiratory hazard. The substance is only used for very short periods during the day and is actually applied by a roller and not sprayed. I have been told by a H&S professional that there is no need for RPE because the exposure is not high enough. Not sure what to do on this one. I was always taught to follow the MSDS and if this states a respiratory hazard then RPE should always be worn but does this come down to the specific situation!
chris.packham  
#2 Posted : 19 January 2020 09:36:27(UTC)
Rank: Super forum user
chris.packham

I will not comment on the need for respiratory protection but keep in mind the potential for skin exposure. Isocyanates are skin sensitisers. There is also evidence that skin exposure can result in a respiratory reaction. There is also evidence that for many skin sensitisers airborne exposure to the chemical can result in a skin (and possibly respiratory) reaction at exposure levels below that of the Workplace Exposure Limit.

"Although respiratory exposures have been the primary concern with isocyanates, skin exposure can also occur and may contribute to sensitization and asthma." -  Skin Exposure to Aliphatic Polyisocyanates in the Auto Body Repair and Refinishing Industry: A Qualitative Assessment, Liu Y et al, Annals of Occupational Hygiene, 2007, 51, 429-439

 “Direct transdermal uptake from air is not routinely considered. Yet the studies outlined in the previous paragraph suggest that, for at least some indoor pollutants, direct dermal uptake from air may occur at rates that are comparable to or larger than inhalation uptake.” – Weschler CJ, Nazarofi WW, Dermal Uptake of Organic Vapors Commonly Found in Indoor Air, Environmental Science & Technology, 2014, 48, 1230-1237

“Direct transdermal uptake from air is not routinely considered. Yet the studies outlined in the previous paragraph suggest that, for at least some indoor pollutants, direct dermal uptake from air may occur at rates that are comparable to or larger than inhalation uptake.” – Weschler CJ, Nazarofi WW, Dermal Uptake of Organic Vapors Commonly Found in Indoor Air, Environmental Science & Technology, 2014, 48, 1230-1237

“Air threshold limits are insufficient to prevent adverse health effects in the case of contact with substances with a high dermal absorption potential.” - Drexler H, Skin protection and percutaneous absorption of chemical hazards, Int. Arch Occup. Environ. Health (2003) 76:359-361

This can vary depending upon the type of isocyanate you are using and its volatility and any other constituents in the mixture, e.g. a solvent such as xylene.

Chris

Roundtuit  
#3 Posted : 19 January 2020 11:05:24(UTC)
Rank: Super forum user
Roundtuit

You do not state which "isocyanate(s)" - it is only EH40 which gives a generic listing i.e. no CAS No covering all variants for a Workplace Exposure Limit.

If it is MDI then this particular substance and its isomers have a market retriction under REACH

https://echa.europa.eu/documents/10162/46cb2ae0-ee6b-4319-8604-b5b1d4a41d53

NOTE: this is applicable to the Consumer market where in the absence of adequate ventilation does require RPE even the Industrial and Professional markets may require RPE based upon application method/use.

An SDS addresses the mixture where supplied - the RPE requirement may not be related to the isocyanate but as Chris has indicated the solvent carrier - Section 3.2 where the hazards for the individual component substances (as 100% product) will show which constituents are contributing to the overall classification.

Example a prosecution from last year where a typical isocyanate solvent DCM was involved:

https://press.hse.gov.uk/2019/05/23/two-companies-fined-after-floor-layer-fatally-exposed-to-toxic-substance/

The opinion you have been provided would likely not be repeated as expert testimony in court - get professional determination of actual task exposure levels to work from.

chris.packham  
#4 Posted : 20 January 2020 10:19:05(UTC)
Rank: Super forum user
chris.packham

In posting what I did wasone concern of mine was that simply considering inhalation exposure on its own is not sufficient. Not only is there abundant evidence of the potential for any route (inhalation, ingestion, skin) to cause a health issue normally associated with exposure via a different route, when dealing with systemic effects we should not lose sight of the fact that what is cricital is the total dose reaching the affected organ or system due to inhalation, ingestion, or skin individually may not be sufficient to require action, but the total dose from multiple routes could well be signficant. Considering each route on its own could well miss the significance of this! A case for biological monitoring?

chris42  
#5 Posted : 20 January 2020 11:44:20(UTC)
Rank: Super forum user
chris42

From as below and specifically notes roller work. 

https://www.hse.gov.uk/construction/healthrisks/hazardous-substances/isocyanates.htm

Respiratory Protective Equipment (RPE) – you may need RPE where ventilation does not provide enough control – particularly in enclosed spaces if you are creating an aerosol (eg by some rollering work) or using products with significant amounts of TDI. Wearers should be fit tested where needed. It is particularly important to select the correct filter. For example, P3 particulate filters provide protection against spray mist but do not protect you from vapours. You will need the right gas / vapour filter for these. Change them at suitable intervals. Check with your supplier if you’re not sure.

I suggest you also consider health surveillance.

Chris

Security image "WiTY" - shame this was not for a different post

chris.packham  
#6 Posted : 20 January 2020 15:04:52(UTC)
Rank: Super forum user
chris.packham

Re health surveillance this is what the HSE ACoP for COSHH states:

Examples where health surveillance is appropriate under the criteria in regulation 11(2)(b) are:

where there have been previous cases of work-related ill health in the workforce/place;

where there is reliance on PPE, eg gloves or respirators, as an exposure control measure; eg printers wearing gloves to protect against solvents used during press cleaning, or paint sprayers using two-pack paints wearing respirators to prevent asthma. Even with the closest supervision there is no guarantee that PPE will be effective at all times;

where there is evidence of ill health in jobs within the industry; eg frequent or prolonged contact with water (termed ‘wet-working’) causing dermatitis in hairdressers and healthcare workers, or breathing in mists from chrome plating baths causing chrome ulcers in platers.

thanks 1 user thanked chris.packham for this useful post.
stevedm on 20/01/2020(UTC)
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