Reaction mass of 1-O-α-D-glucopyranosyl-D-mannitol and 6-O-α-D-glucopyranosyl-D-glucitol

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

The PBT Assessment for Reaction mass of 1-O-α-D-glucopyranosyl-D-mannitol and 6-O-α-D-glucopyranosyl-D-glucitol, i.e. Isomalt is based on the criteria set out in the “Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT Assessment” (ECHA, 2017).

Persistence:

No data on Isomalt itself are available. However, the biodegradation potential was assessed based on the constituents of Isomalt and read-across data available for the source substance Isomaltulose. QSAR calculations were done for both of the main components, i.e. 1-O-α-D-glucopyranosyl-D-mannitol (1,1-GPM) and 6-O-α-D-glucopyranosyl-D-glucitol (=6-O-α-D-glucopyranosyl-D-sorbitol) (1,6-GPS). As the sugar alcohols in both of the disaccharides are isomers of each other the prediction is the same for both components of Isomalt, i.e. readily biodegradable.

The QSAR prediction is corroborated by the findings of a ready biodegradability study available for Isomaltulose (=6-O-alpha-D-glucopyranosyl-D-fructose), used as source substance in a read-across approach as detailed in the analogue justification attached to IUCLID section 13. In this study according to OECD guideline 301 B and GLP the test substance was degraded to 90% after 28 days, fulfilling the 10 day window, and thus considered as readily biodegradable.

Based on the results detailed above and in general on the molecular structure of the constituents of Isomalt, it is considered readily biodegradable and therefore not P and not vP.

Bioaccumulation:

Isomalt has a low potential for bioaccumulation based on low log Kow values in the range of -4.2 to -3.7.

Furthermore, Isomalt is a widely used and as safe classified food additive. The metabolism of sugars is well known, and thus based on the molecular structure of the constituents of Isomalt, and their natural occurrence and role in common metabolic pathways, bioaccumulation in organisms is not expected.

Therefore, Isomalt exhibits a low potential for bioaccumulation and is considered not B and not vB.

Toxicity:

Considering the environment no experimental data on the aquatic toxicity of Isomalt are available. Thus, for all trophic levels effect values are either derived by QSAR predictions for the components of Isomalt or read-across from the analogue substance Isomaltulose. No toxic effects towards aquatic freshwater organisms of all three trophic levels (fish, invertebrates, algae) were identified. A chronic value of 1770 g/L is available. This value was derived by QSAR predictions for both components of Isomalt, i.e.1-O-α-D-glucopyranosyl-D-mannitol (1,1-GPM) and 6-O-α-D-glucopyranosyl-D-glucitol (=6-O-α-D-glucopyranosyl-D-sorbitol) (1,6-GPS)). In general based on the molecular structure of the constituents of Isomalt, their intrinsic properties and their natural occurrence and role in common metabolic pathways, Isomalt is considered to cause no adverse effects at all towards aquatic organisms in the environment (see details in section 6 of IUCLID). Furthermore, according to Directive 67/548/EEC no classification applies for carcinogenicity (category 1 or 2), mutagenicity (category 1 or 2) or toxicity to reproduction (category 1, 2, or 3) and/or no classification applies according to the consolidated version of Regulation (EC) No 1272/2008 and further amendments (ATPs) for carcinogenicity (category 1A or 1B), germ cell mutagenicity (category 1A or 1B) or toxicity to reproduction (category 1A, 1B, or 2). Further, there is no evidence of chronic toxicity, as identified by the classifications T, R48 or Xn, R48 according to Directive 67/548/EEC or specific target organ toxicity after repeated exposure (STOT RE category 1 or 2) according to Regulation EC No 1272/2008.

Therefore, Isomalt is not toxic and is considered not T.

In conclusion Isomalt is not PBT/vPvB.