Fatty acids, C16-18 (even numbered) saturated and C16-20 (even numbered) unsaturated, lithium salts

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

a short-term toxicity study does not need to be conducted because exposure of humans via inhalation in production and/or use is not likely as based on the provided thorough and rigorous exposure assessment

Justification for type of information:

The category members are almost exclusively produced and used directly in grease form. They have vapour pressures of less than 10 E-10 Pa and melting points of greater than 160°C, so the potential for the generation of inhalable forms is low, also the use of the grease forms will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be unlikely to occur. Only two category substances (Fatty acids C16-18, lithium salts and Lithium 12-hydroxystearate) are produced to some extent in solid form and then subsequently formulated into grease by occupational downstream users. From the granulometry data on the solid, generation of dusts of an inhalable size cannot be excluded. General accepted OELs derived for inert (nuisance) dust/particulates not otherwise classified (PNOCs), of 10 mg/m³ for chronic and 20 mg/m³ for acute exposure to inhalable dust and of 3 mg/m³ for chronic and of 6 mg/m³ for acute exposure to alveolar (respirable) dust) are applicable and must be adhered to, to avoid non-specific inhalation dust toxicity. Thus, at the production, and occupational downstream users' sites, the exposure to dusts/aerosols can be assumed as insignificant due to personal protective and engineering RMMs routinely implemented to comply with the general dust OELs. Route-to-route extrapolation from comprehensive long-term oral toxicity data to long-term inhalation toxicity would result in a DNEL long-term exposure – systemic effects worker of 287 mg/m³ (oral DNEL of 41 mg/kg bw/day multiplied by 70 kg bw and divided by 10 m3 per person – cf ECHA TGD R8 Example R8.1). This value is considerably higher than the general dust limits, which apply in any case. Thus, by adherence to the general dust limits, the risk to humans can be considered to be sufficiently controlled. In accordance with ECHA REACH TGD R.8, the general dust limits are used as DNEL surrogate. In accordance with REACH Regulation, Annex IX, 8.6.2, column 2 as well as Annex XI, 1, the performance of additional repeated dose toxicity studies is not justified due to exposure as well as toxicological considerations.

Results and discussion

Target system / organ toxicity

Critical effects observed:

not specified