We reported, in edition 270 of BC Disease News (here), that the European Commission had asked the European Chemicals Agency (ECHA) to recommend, in support of continued reform of the Chemical Agents Directive (CAD) 98/24/EC and the Carcinogens and Mutagens Directive (CMD) 2004/37/EC:
- Binding time-weighted average (TWA) occupational exposure limit(s) (OEL);
- Biological limit value(s) (BLV); and
- Health surveillance measures and/or appropriate notations,
for lead and its compounds and diisocyanates.
Since then, the ECHA has opened two consultations, both of which request relevant comments and evidence from ‘interested parties such as companies (suppliers, distributors, importers etc.), trade associations and any other stakeholders or Member State Authorities’:
‘[These calls intend] to gather information on uses, exposure, health effects, toxicology, epidemiology and modes of action on lead and its compounds [and diisocyanates]. The information gathered will form the basis when drafting the scientific report[s]’.[i]
The ECHA will therefore use the information obtained to assess the work-related health risks of cumulative exposure.[ii]
In the background note, supplementary to the consultation on lead and lead compounds, the Agency explains that:
‘Lead and lead compounds are harmful to human health and are generally classified as toxic to reproduction (fertility and development) and toxic following prolonged and repeated exposure (adverse effects on several organs).
Furthermore, lead compounds are also hazardous to the aquatic environment (acute and long-term effects)’.[iii]
Lead compounds are commonly used:
- In the production of lead metal and its compounds;
- In the manufacturing processed of batteries, ceramics, jewellery, glass and pigments; and
- In the pottery, shipbuilding, construction, demolition and scrap industries.
By contrast, the Agency’s supplementary background note to the consultation on diisocyanates does not provide details on potential health risks, nor exposure sources.[iv]
However, the American Chemistry Council states that:
‘Diisocyanates are a family of chemical building blocks mainly used to make polyurethane products, such as rigid and flexible foams, coatings, adhesives, sealants and elastomers’.[v]
Common types of diisocyanates include:
- Methylenebis(phenyl isocyanate) (MDI);
- Toluene diisocyanate (TDI);
- Hexamethylene diisocyanate (HDI);
- Naphthalene diisocyanate (NDI);
- Methylene bis-cyclohexylisocyanate (HMDI)(hydrogenated MDI); and
- Isophorone diisocyanate (IPDI).[vi]
What is more, the Health and Safety Executive (HSE) states that related exposures can cause:
- Irritation of the eyes, nose and throat;
- Dermatitis; and
- Occupational asthma (more significant risk for sprayers).[vii]
Both consultations close on 30 June 2019, after which the ECHA’s Risk Assessment Committee (RAC) will develop its opinion, share it with the Commission [to inform the Advisory Committee on Safety and Health at Work (ACSH)] and publish it on the ECHA website.
The Current UK Position
According to EH40/2005, the following British workplace exposure limits (WEL) and biological monitoring guidance values (BMGV) are set, in conjunction with the Control of Substances Hazardous to Health (COSHH) Regulations 2002:
- The WELs for all isocyanates, except MDI, are ‘0.02 mg/m3’ (long-term 8-hour TWA) and ‘0.07 mg/m3’ (short-term 15-minute period);
- The WEL for MDI is ‘0.02 ppm’; and
- The BMGV for HDI, IPDI, TDI and MDI is ‘1 μmol isocyanate-derived diamine/mol creatinine in urine’, sampled at the end of the exposure period.[viii]
Elsewhere, current UK exposure limits for occupational lead exposure are instituted by Regulation 2(1) of The Control of Lead at Work Regulations 2002, in which:
- The OEL for lead, other than lead alkyls (tetraethyl lead or tetramethyl lead), is 0.15 mg/m3;
- The OEL for lead alkyls, is 0.10 mg/m3; while
- The action levels for lead exposure are blood-lead concentrations of 25 μg/dl (for women of a reproductive capacity), 40 μg/dl (for persons under the age of 18 and women not of reproductive capacity) and 50 μg/dl (for all other employees).
[i] ‘Occupational exposure limits - Call for comments and evidence’ (17 April 2019 ECHA) <https://echa.europa.eu/-/echa-weekly-17-april-2019> and <https://echa.europa.eu/oels-cce-current-consultation/-/substance-rev/23201/term> accessed 23 April 2019.
[ii] ‘ECHA Weekly’ (17 April 2019 ECHA) <https://echa.europa.eu/-/echa-weekly-17-april-2019> accessed 23 April 2019.
[iii] ‘Call for evidence: Scientific evaluations of health-based exposure limits at the workplace for lead and its compounds – Background note’ (17 April 2019 ECHA) <https://echa.europa.eu/documents/10162/045132e9-d8b9-e19e-40ec-b0393ec53492> accessed 23 April 2019.
[iv] ‘Call for evidence: Scientific evaluations of health-based exposure limits at the workplace for diisocyanates – Background note’ (17 April 2019 ECHA) <https://echa.europa.eu/documents/10162/5a6e6b4c-cf74-5e59-9ad3-a2cc140daf64> accessed 23 April 2019.
[v] ‘Diisocyanates Explained’ (American Chemistry Council) <https://dii.americanchemistry.com/Diisocyanates-Explained/> accessed 23 April 2019.
[vi] Isocyanates (23 April 2014 CDC) <https://www.cdc.gov/niosh/topics/isocyanates/default.html> accessed 23 April 2019.
[vii] ‘Construction hazardous substances: Isocyanates’ (HSE) <http://www.hse.gov.uk/construction/healthrisks/hazardous-substances/isocyanates.htm> accessed 23 April 2019.