Cetylpyridinium chloride

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Type of Data	PBT-Criterion	vPvB-Criterion		Value for Substance	Indication or Determination
Persistence
Ready Biodegradability test	Readily biodegradable (not P)	Readily biodegradable (not vP)		Not readily biodegradable in ready biodeg. assay (0% O2consump. in 28 d)	Potentially P, potentially vP
Enhanced ready biodegradability test	Readily biodegradable (not P)	Readily biodegradable (not vP)		ND
Inherent Biodegradability (Zahn-Wellens OECD 302B)	≥70% mineralization (DOC removal) in 7 d; log phase≤3 d (not P)	NA		ND
Inherent Biodegradability (MITI II OECD 302C)	≥70% mineralization (O2uptake) in 14 d; log phase≤3 d (not P)	NA		ND
Biodegradation Simulation testing	t1/2> 60 days in marine water (P), or	t1/2> 60 days in marine, fresh- or estuarine water vP), or		ND
	t1/2> 40 days in fresh or estuarine water (P), or			ND
	t1/2> 180 days in marine sediment (P) or	t1/2> 180 days in marine, fresh- or estuarine sediment (vP), or		ND
	t1/2> 120 days in soil (P)	t1/2> 180 days in soil (vP)		70.7% mineralization in soil in 28 days (t1/2< 120 days)	Not P, not vP
Inherent biodegradability	< 20% degradation (P)	NA		ND
Abiotic degradation
Photodegradation
Hydrolysis				ND
Bioaccumulation
Octanol-water partition coefficient (screening)	Log Kow≤4.5 (not B)	Log Kow≤4.5 (not vB)	Log Kow= 1.71		not B not vB
Biomagnification	BMF > 1 (B)	BMF > 1 (vB)	ND
Type of Data	PBT-Criterion	vPvB-Criterion	Value for Substance		Indication or Determination
Bioaccumulation, continued
Aquatic bioaccumulation (experimental determination; fish or invertebrates)	BCF > 2000 L/kg (B)	BCF > 5000 L/kg (vB)	ND
Aquatic bioaccumulation (QSAR)	BCF > 2000 L/kg (B)	BCF > 5000 L/kg (vB)	ND
Toxicity
Avian toxicity (subchronic, chronic or reproductive)	NOEC < 30 mg/kg food (T)	NA	ND
Short-term aquatic toxicity	L(E)C50 < 0.1 mg/L (T)	NA	0.0041 mg/L (EC50, acute daphnid toxicity test)		Presumably T
Short-term aquatic toxicity	L(E)C50 < 0.01 mg/L (T)	NA	0.0041 mg/L (EC50, acute daphnid toxicity test)		T
Long-term aquatic toxicity	NOEC (long-term) < 0.01 mg/L (T), or	NA	ND
Mammalian toxicity	Classified as carcinogenic (Cat 1A or 1B), mutagenic (Cat 1A or 1B) or toxic for reproduction (Cat 1A,1B or 2) (T)	NA	Not classified.		Not T
	Evidence of chronic toxicity : STOT-RE Cat 1 or 2): (T)	NA	No evidence.		Not T

 

Screening criteria

Definitive criteria

Additional considerations

NA: not applicable

ND: no data available

Definitive determinations in boldface type

 

Considerations and Conclusions:

Although the substance did not exhibit ready degradability in a ready biodegradability closed bottle test, the substance has been shown to be rapidly degradable in a soil aerobic degradation simulation test.  Mineralisation of 70.7% was achieved in 28 days, and 80.8% mineralisation was reported in 121 days, showing that the substance half-life in soil was below the indicator of a persistent (P) substance (degradation of half-life in soil > 120 days), and also below the indicator of a very persistent (vP) substance (i.e., a degradation half-life in soil > 180 days). The soil compartment is a relevant compartment for the evaluation of degradation, since the substance has been shown to partition strongly to soils; the reported adsorption coefficient of the substance was determined in five soil types, ranging from K_oc= 60,000 L/kg in sand soil type, to K_oc> 832,000 in a clay/clayey loam soil type. In accordance with ECHA guidance, 70% ultimate degradability in 28 days indicates that the criteria for P and vP are not fulfilled. Therefore, the substance is determined to be “definitively not P” and “definitively not vP”.

 

Screening-level data indicate that the substance is not bioaccumulative (not B) and not very bioaccumulative (not vB), based on the predicted octanol-water partition coefficient (log K_ow) of 1.71, which is substantially below the screening criterion (log K_ow≤ 4.5) for both “not B” and “not vB”. However, the substance is a surface-active agent, and ionizes in the aquatic milieu. Therefore, the log K_ow may not be a reliable predictor of the potential for bioaccumulation, and an experimentally-determined value for log K_ow is not available. Aquatic bioaccumulation testing was not conducted on the substance, and therefore the bioaccumulative properties of the substance cannot be definitively determined. However, available information indicates that the substance has a low potential for aquatic bioaccumulation, based on its strong adsorption to soils, sediment and activated sludge, and demonstrated rapid aerobic biodegradation; substances that degrade rapidly in the environment “are likely to be rapidly metabolized in organisms” in accordance with ECHA guidance (ECHA, Guidance on information requirements and chemical safety assessment, Chapter R.7C, Endpoint-specific guidance, Section R.7.10.3.4, p. 26, November 2012). Therefore, although a definitive determination has not been made, the substance is considered to be “presumably not B” and “presumably not vB”. 

The evaluation of short-term aquatic toxicity tests indicate that aquatic invertebrates are the most sensitive trophic level; the 48-h EC₅₀values reported from two acute freshwater toxicity tests on Daphnia magna were 0.00918 mg/L and 0.0041 mg/L, respectively. These results provide a definitive determination that the substance is toxic (“definitively T”) with respect to aquatic organisms. The substance does not exhibit the properties of a carcinogenic, mutagenic or reproductive toxicant [CMR], nor does the substance exhibit specific target organ toxicity in a repeated-dose study [STOT-RE]). These results provide a definitive determination that the substance is not toxic with respect to mammalian endpoints.

 

Therefore, although a complete definitive determination cannot be made with respect to the bioaccumulation endpoint, it has been shown by definitive data that the substance is “not P”, “not vP”, and “T” (based on aquatic toxicity). It is not necessary to have definitive criteria for all five endpoints to make the determinations as to whether the substance is “not PBT” and “not vPvB”. The determination only requires that “each of the three properties persistency, bioaccumulation and toxicity need to be considered in conjunction” (Chapter R.11, “PBT Assessment”, Guidance on information requirements and chemical safety assessment, ECHA, November 2012, Section R.11.1.2.2, p. 15).

 

In summary, based on data available to date, the substance is “not PBT” (definitively not P, presumably not B, and definitively T based on aquatic endpoints) and is “not vPvB” (definitively not vP, presumably not vB).