Man-made vitreous (silicate) fibres with random orientation with alkaline and alkali earth oxides (Na2O+K2O+CaO+ MgO+BaO) content greater than 18% by weight and fulfilling one of the CLP Regulation Annex VI Note Q conditions

Endpoint summary

Description of key information

In accordance with Section 1 of REACH Annex XI, an additional skin sensitisation study does not need to be conducted. Given the existing historical human data and taking a weight-of-evidence approach, there is no skin sensitisation concern of Note Q MMVFs.

 

Indeed, epidemiological data show no potential for skin sensitization. In addition, due to the specific form of fibers, no skin penetration is expected. The OECD guidelines cannot apply for such substance.

1.1.1     Epidemiological data

Mineral wool fibres (made of glass, stone/rock or slag) and fibreglass were both used as read-across substances for Note Q MMVFs due to their similarities in the chemical components. For short-term exposure (i.e. from hours to a few days), the difference in biopersistence between Note Q and non-Note Q MMVFs is not considered relevant. As mineral wool fibres, fibreglass and Note Q MMVFs have nearly identical chemical components, mineral wool fibres and fibreglass are deemed as suitable read-across substances for Note Q MMVFs.

 

Human data of the 4 epidemiological studies (see IUCLID sections 7.10.4) on mineral wool fibres and fibreglass provide evidence to indicate no concern of skin sensitising potential after exposure. In particular, the study from Jolanki et al., (2002). In that study, 11532 new cases of occupational dermatoses were reported to the Finnish Register of Occupational Diseases (FROD) during the 10-year observation period 1990–99. Altogether, 3667 (31%) cases were diagnosed as Allergic Contact Dermatitis (ACD), 4498 (39%) as Irritant Contact Dermatitis (ICD) and 3367 (29%) as other occupational dermatoses, of which 1680 were contact urticaria and protein contact dermatitis, and 633 were unspecified contact dermatoses (either ACD or ICD). The incidence of occupational dermatoses was 52 new cases per 100000 person years.

The most common causes of all occupational dermatoses were (percentage of all occupational dermatoses in brackets): detergents (13%), rubber and rubber chemicals (12%), plastic chemicals (9%), wet and dirty work (9%), and animal epithelia (7%).

A total of 63 cases of occupational dermatoses from synthetic mineral fibres were reported to the FROD during 1990–99. 56 of these (89%) were diagnosed as ICD. Only 2 cases of ACD, both from rock wool, were reported. 84% (53 out of 63) of the cases were due to mineral wool or glass filaments; half of the cases, according to a rough estimate based on the occupations of the notified cases, were due to mineral wool used in construction work, insulation, etc., and half due to glass filaments used in lamination work. According to the data from FROD and experience of authors, carpenters, building workers and insulation workers have the highest risk of ICD from wool-like synthetic mineral fibres (mineral wool). 4 cases of occupational dermatosis in carpenters, 5 in building workers and 2 in insulation workers were reported from synthetic mineral fibres. In these occupations, less than 10% (4/41 and 4/65, respectively) were due to MMVF. Only 10 cases of occupational dermatosis were reported in insulation workers. Out of 6 cases of ICD, 2 (33%) were from synthetic mineral fibres (1 from mineral wool, 1 from unspecified synthetic mineral fibres), and the rest from various causes. 2 cases were diagnosed as ACD, 1 from rubber chemicals and 1 from isothiazolinones. In addition, 2 cases with other diagnoses were reported. Based on the numbers of employed persons in the occupations, for every 100000 employed workers, in total 16 cases of occupational ICD were annually reported in carpenters, 43 in building workers and 27 in insulation workers.Of these, only 1.6 cases in carpenters, 2.7 in building workers and 9.1 cases in insulation workers were due to synthetic mineral fibres. The incidence of ICD due to MMVF for all the 3 occupations was significantly higher than the incidence for all occupations (Fisher’s Exact Test; p0.001). A difference in the incidence of ICD due to MMVF was found between carpenters and insulation workers at the 7% level of significance.

A statistically significant difference was not observed in the incidence of ICD due to MMVF between carpenters and insulation workers. However, the risk of ICD due to MMVF among insulation workers, assumed to be the most exposed group, is probably higher than among carpenters. A significant difference could not be observed because of the small number of cases. This statement is supported by the fact that 20% of all occupational dermatoses in insulation workers were ICD due to MMVF. Thus those who are most exposed, i.e. insulation workers, have the highest risk. “However, the mineral wool used in construction work, insulation, etc., cannot be considered to be a common cause of occupationally induced ICD. Based on the actual data from FROD, we are not able to make a clear-cut decision on the classification of MMVF as ‘irritating to skin’. However, in our opinion the information on harmful skin effects of MMVF is useful to exposed persons in the prevention of the effects.”

The other 3 studies showed that the reported skin effects (e.g. after patch test performance) by mineral wool fibres and fibreglass were of mechanical and not of allergic nature (Björnberg & Löwhagen, 1977; Possick et al., 1970; Wang et al., 1993), which supports the conclusion that mineral wool fibres and fibreglass do not act as skin sensitisers.

The study of Björnberg & Löwhagen, 1977 compared reactions after patch tests with Rockwool powder (without any fibres) and Rockwool as sharp fibres. With the first one, no reaction was observed (0/10); with the second one skin reactions were reported (8/10). “it seems therefore that the typical properties of these fibres produce these skin reactions mechanically”.

Possick et al., 1970 investigated the prevalence and significance of work-related dermatitis. Authors found that skin irritation occurs in most new workers and confirmed that the major cause is mechanical irritation by the glass particles, and the sequelae of scratching. Allergy does not play a part in the development of skin irritation from fibrous glass. This is demonstrated clinically by the fact that, although allergy requires an incubation period of at least ten days, most workers experience difficulty during the initial week of exposure. The dermatitis is caused by short glass fibres which temporarily pierce the epidermis. It confirmed that allergy does not plan a role in the dermatitis.

Wang et al., 1993 reported two cases of sever fiberglass dermatitis. Medical investigations confirmed no allergic reactions.

 

1.1.2         Fibres cannot cross the skin barrier

Liposolubility of a substance is a pre-requisite for skin penetration, along with its shape: physically speaking, a liquid or spherical powder has statistically much more chance to penetrate the skin than fibrous substances.

MMVF are slightly soluble in water but not soluble in lipophilic media, hence MMVF are slightly hydrophilic and not lipophilic. In addition, MMVF are fibres.

Consequently, MMVF cannot cross the skin barrier.

1.1.3         The very limited applicability and relevance of OECD tests to mineral fibres

OECD 442c, OECD 442d, OECD 442e for in vitro testing are not applicable to UVCB substances nor to inorganic substances. As MMVF are inorganic and a UVCB substance, they are out of the applicability domain of such tests.

In vivo testing cannot apply as skin penetration is a pre-requisite and MMVF cannot cross the skin barrier.

 

 

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

The full waiving argumentation is detailled in the document "Skin sensitization: waiving argumentation" in the box below.
The studies mentionned as weight of evidence are detailled in the endpoints of the section 7.10.4 (sensitisation data, human) - the pdf printed version of these endpoints is also enclosed in the box below.

No data for the target substance (Note Q man-made vitreous fibres) are available. Thus, data from appropriate read-across substances (mineral wool fibres and fibreglass) were used to assess the potential for skin sensitisation. An in vitro or in vivo skin sensitisation study does not need to be conducted because historical human data on skin sensitisation from 4 studies are available (see IUCLID sections 7.10.4) and were assessed in a weight-of-evidence approach. Human data provide evidence to indicate no concern of skin sensitising potential of mineral wool fibres and fibreglass after exposure. In particular, the study from Jolanki et al., (2002) reported only a very low incidence of allergic contact dermatitis possibly attributable to occupational exposure to stone/rock wool in Finnish workers (2 out of 11,532 cases with occupational dermatoses recorded during 1990-1999), which was considered not statistically significant. The other 3 studies showed that the reported skin effects (e.g. after patch test performance) by mineral wool fibres and fibreglass were of mechanical and not of allergic nature (Björnberg & Löwhagen, 1977; Possick et al., 1970; Wang et al., 1993), which supports the conclusion that mineral wool fibres and fibreglass do not act as skin sensitisers.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The testing for skin sensitisation is waived, because MMVF note Q fibres are inorganic fibres, whose physicochemical properties suggest a low potential to cross biological membranes and consequently a low potential to penetrate the skin. Skin penetration is prerequisite in the LLNA test. It is evaluated that MMVF note Q fibres will not give any response in the LNNA test. Furthermore, many years of workers exposure has not revealed cases of skin sensitisation. It is assessed that MMVF note Q fibres are not a skin sensitiser in humans.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In accordance with Section 1 of REACH Annex XI, skin sensitisation study does not need to be conducted. Given the existing historical human data and taking a weight-of-evidence approach, there is no skin sensitisation concern of Note Q MMVFs.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Workers have been exposed to man-made vitreous fibres (MMVF) by inhalation for many years without any indication for induction of respiratory sensitisation. Furthermore, MMVF note Q fibres do not translocate in the body after inhalation. It assessed that MMVF note Q fibres do not induce respiratory sensitisation in humans.

Migrated from Short description of key information:

MMVF note Q fibres are assessed not to be a respiratory sensitiser in humans. MMVF note Q fibres shall not be classified as a respiratory sensitiser according to the criteria in Council Directive 67/548/EEC and Regulation (EC) 1272/2008.  

Justification for classification or non-classification

MMVF note Q fibres are inorganic fibres, whose physicochemical properties suggest a low potential to cross biological membranes, making it unlikely that MMVF note Q fibres should possess sensitising properties. Furthermore, many years of worker exposure to mineral wool (MMVF) by dermal contact and by inhalation has not in known cases of skin or respiratory sensitisation. It is assessed that MMVF note Q fibres are not a skin sensitiser or a respiratory sensitiser. MMVF note Q fibres shall not be classified as a skin or respiratory sensitiser according to the criteria in Council Directive 67/548/EEC and Regulation (EC) 1272/2008.

In accordance with Section 1 of REACH Annex XI, skin sensitisation study does not need to be conducted. Given the existing historical human data and taking a weight-of-evidence approach, there is no skin sensitisation concern of Note Q MMVFs.