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Category name:
Montan waxes and related waxes

Justifications and discussions

Category definition:
All category members substances are derived from naturally occurring montan waxes by chemical modification. They are of high structural similarity with only very minor differences in their physico-chemical properties (high molecular weight, melting point, flammability, solubility, octanol-water partition coefficient) as well as in their toxicological and ecotoxicological behavior.
Category rationale:
REPORTING FORMAT FOR THE CATEGORY APPROACH

1. CATEGORY HYPOTHESIS
The category covers the multi-constituent substances identified in Table 1 of the attached category document.
The original category was established for the 2010 registration deadline of these substances under REACH (> 1000 tonnes/a, November 2010), and comprised three category members, i.e. montan waxes, types S, E and OP. This category was extended to a total of 10 related montan waxes for the 2013 REACH registration (100 to 1000 tonnes/a) deadline by the Lead registrant (i.e. included also Montan waxes, type CAV 102,O, WE4, WM31, WE40, KPS, and NaV101). This category is now extended further to include the Montan wax, type LG, which is registered for the 2018 REACH registration deadline (10 to 100 tonnes/a).
All these substances are derived from naturally occurring montan waxes by chemical modification.
The category hypothesis is that all members are of high structural similarity with only very minor differences in their physico-chemical properties (high molecular weight, melting point, flammability, solubility, octanol-water partition coefficient) as well as in their toxicological and ecotoxicological behavior.
All members of the category share a very similar chemical structure with long, mainly even-numbered alkanoic acids of a similar chain length profile (alkanoic units), the corresponding esters with alkyl alcohols of the same chain length distribution, ethanediol, butanediol or glycerol and the corresponding calcium salts. Slight variations in composition and the distribution of chain lengths between members of the category are not expected to have a substantial impact on their physico-chemical, toxicological and ecotoxicological properties. The montan wax, type WM31 deviates insofar as tallow acids (saturated long chain fatty acids with chain length of C12-C22, which are derived from hydrogenated animal fat) supplement the montan wax basis derived from fossil plants. However the composition and the properties of these animal fatty acids are very similar to the fossil plant fatty acids.
All members have comparable physico-chemical properties (e.g. melting point, density, low solubility in water, partition coefficient octanol-water) and exhibit low toxicity in mammals and environmental organisms. Some minor differences are observed in ready biodegradability experiments.
Thus, the available toxicological and ecotoxicological data can be used for all other members of this category.
For repeated-dose toxicological endpoints the category is supplemented with the following substances, showing very similar chemical structures, but are originating from other sources (non-fossil plants):
- D-003 (origin: sugar cane wax): predominantly even-numbered long chain fatty acids (mainly C24-C36 with a maximum of C28-C32)
- Carnauba wax (origin: leaves of tropic palms): esters of even-numbered long chain fatty acids and alcohols (mainly C14-C34 acids with a maximum of C20-C30, mainly C20-C36 alcohols with a maximum of C30-C34), free aliphatic long chain fatty acids and alcohols, esters of ω-hydroxy-carboxylic acids with mainly C20-C36 alcohols with a maximum of C30-C34, esters of p-hydroxy- and p-methoxycinnamic acid
- Policosanol (origin: sugar cane wax): mostly even numbered long chain fatty alcohols (C24-C34), mainly octacosanol (C28)
These substances have been shown a similar composition in comparison to the corresponding refined montan wax derivatives, whereas Carnauba wax contains some additional constituents, derived from cinnamic acid (Lange and Wildgruber, 2006; Matthies, 2001).

2. CATEGORY JUSTIFICATION
The members of the category are structurally similar, consisting of mostly even-numbered very long saturated alkyl chains with various functional groups.
The seven montan waxes substances are solids at room temperature. They have similar (low) melting points and densities. Their solubility in water is low and the partition coefficients octanol-water are ≤ 2.0, see data matrix below.
Based on the available data, the category members show no toxicity after single oral exposures, no irritating effects to skin or eye, no skin sensitizing effects, repeated dose toxicity, no mutagenic properties and no biologically significant effects to aquatic, terrestrial and sediment organisms as well as bacteria. The category members are of limited biodegradability (see PBT/vPvB assessment).