Tetrakis(hydroxymethyl)phosphonium chloride, oligomeric reaction products with urea

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence assessment:

Screening criteria:

THPC-urea (and THPC) are not readily biodegradable. But according to a 31P-NMR analytical monitored Zahn-Wellens test within 14 days a complete degradation to primary metabolites (THPO) occurs.

Data on the biodegradation in the sediment and soil compartments are not available. The test item hence should be considered as inherent biodegradable.

The substance is hydrolytically stable under neutral and acidic environmental condition but shows a tendency for less stability in basic environments. Photodegradation in air seems not to be a relevant degradation process for this substance since the test item has a negligible vapour pressure. There is no information available about photodegradation of the substance in sediment or soil.

Conclusion of Persistence assessment:

The substance should not be considered as persistent oras very persistent (vP) in the environment.

Bioaccumulation assessment:

Screening criteria:

According to the screening criteria for bioaccumulation (B for bioaccumulative, vB for very bioaccumulative) given in the technical guidance provided by ECHA (ECHA 2008, Guidance on information requirements and chemical safety assessment, Chapter R.11), a substance does not fulfil the B and the vB criterion if its log Kow ≤ 4.5. Based on solubility tests, the octanol-water partition coefficient for the substance is calculated as log Kow < -2.8, which is far below the B and the vB criterion.

Conclusion of bioaccumulation assessment:

The substance is not considered to be bioaccumulative,neither fulfilling the B nor the vB criterion.

Toxicity assessment

Criteria based on Annex XIII of REACH:

- Not T based on the following criteria:

·   EC50 / LC50  >= 0.1 mg/L for marine / freshwater organisms (short-term toxicity),
EC10 / NOEC >= 0.01 mg/L for marine / freshwater organisms (long-term toxicity):

All short-term aquatic toxicity values are > 0.1 mg/L according to the aquatic toxicity values of the read across substances THPC and THPS. The 96h-NOEC value for algae for the read-across substance THPS is > 0.01 mg/L.

·   Substance is not classified as carcinogenic (cat 1 or 2), mutagenic (cat 1 or 2), or toxic for reproduction (cat 1 or 2) according to Directive 67/548/EEC or carcinogenic (cat 1A or 1B), germ cell mutagenic (cat 1A or 1B), or toxic for reproduction (cat 1A or 1B) according to Regulation EC No 1272/2008.

·   No other 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 cat 1 or 2) according to Regulation EC No 1272/2008.

  

Conclusion of Toxicity assessment:

The substance is considered to be toxic to the aquatic environment, but this is not the case for its main degradation metabolite THPO.

The substance shows mutagenic toxicity in-vitro, but not in-vivo.

The substance shows primary local toxicity. After repeated exposure neither the oral chronic NOAEL = 5 mg/kg bw/kg nor the chronic dermal NOAEL = 100 mg/kg bw/kg is conclusive for classification for systemic toxicity (STOT).

  

Likely routes of exposure:

No emission characterization is required since the substance is not a PBT or vPvB substance.