1H-Inden-1-one, 2,3-dihydro-5,6-dimethoxy-3,3-dimethyl-2-(phenylmethylene)-

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence (P/vP)

Based on the available biodegradability test, SymHelios® 1031 is not readily biodegradable

(degradation <10% after 28 days determined in an OECD 301-F study). Therefore, a certain potential

for persistency cannot be excluded.

Bioaccumulation (B/vB)

Several current models were used for a screening to estimate a BCF (Bioaccumulation factor) for

SymHelios® 1031 using either Kow or the aqueous solubility as input parameters. None of the used

models predicted BCFs > 1200 L/Kg ww.

Thus, the screening criteria for "bioaccumulative" (BCF > 2000; LogKow > 4.5) or "very

bioaccumulative" (BCF > 5000) are not fulfilled, such as the logKow of 3.73 at 23 °C for the substance

SymHelios ® 1031.

Therefore, SymHelios® 1031 does not qualify as a “B” or a “vB” substance.

Toxicity (T)

The T criteria to clarify if a substance is toxic are not fulfilled for the substance SymHelios® 1031 for

the following reasons:

1. Regarding aquatic toxicity, the results of the short-term tests indicate that a 96-h LC50 of 0.83 mg/L

was determined for the most sensitive species (i.e., fish; species: Danio rerio). According to ECHA

guidance, a substance is considered to potentially meet the T criteria when an acute LC/EC50 value

from a standard LC/EC50 toxicity test is less than 0.1 mg/L.

According to the REACH legislation (Annex XIII), a substance fulfils the toxicity criterion (T) regarding

aquatic toxicity when the long-term NOEC for marine or freshwater organisms is less than 0.01 mg/L.

Chronic data available for algae indicate that NOEC and 72-h ErC10 values are far above 0.01 mg/L

(ErC10 > 1.78 mg/L).

Regarding aquatic toxicity, the Toxicity criteria are not fulfilled for the substance SymHelios® 1031.

2. Regarding carcinogenicity, mutagenicity, or reproductive toxicity, a substance is considered to

potentially meet the T criteria if it classifies for carcinogenicity (cat 1/2), mutagenicity (cat 1/2), or

reproductive toxicity (cat 1/2/3). None of the relevant tests conducted with SymHelios® 1031, including

a 28-d oral toxicity study in rats (OECD 422 Combined repeated dose toxicity study with

reproduction/developmental toxicity screening) and an in vivo micronucleus assay in bone marrow of

mice (OECD 474) indicate a potential for carcinogenicity, mutagenicity, or reproductive toxicity.

Regarding carcinogenicity (cat 1/2), mutagenicity (cat 1/2), or reproductive toxicity (cat 1/2/3), the

Toxicity criteria are not fulfilled for the substance SymHelios® 1031.

3. Regarding other evidence of chronic toxicity, a substance is considered to potentially meet the T

criteria if it classifies T, R48, or Xn, R48 according to Directive 67/548/EEC. None of the relevant tests

conducted with SymHelios® 1031, including a 28-d oral toxicity study in rats (OECD 422 Combined

repeated dose toxicity study with reproduction/developmental toxicity screening) and an in vivo

micronucleus assay in bone marrow of mice (OECD 474) indicate a potential for chronic toxicity

according to Directive 67/548/EEC. Regarding chronic toxicity, the Toxicity criteria are not fulfilled for

the substance SymHelios® 1031.

Thus, SymHelios® 1031 does not qualify as a “T” substance.

Conclusion:

In accordance with current ECHA guidance and REACH regulation (EC) No 1907/2006, the

substance SymHelios® 1031 does not fulfill the criteria of PBT or vPvB.

Further environmental toxicity and fate testing, including aquatic chronic toxicity, may be

considered if SymHelios® 1031 will be manufactured at a higher tonnage band.