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

Endpoint summary

Description of key information

LD50 oral (Combined Male/Female rats) = 625 mg Active Ingredient (AI)/kg bw. Therefore, THPC-urea is considered as harmful by oral route

LD50 dermal (rat): > 1306 mg AI/ kg BW. Therefore, THPC urea is considered as not harmful by dermal route.

Acute toxicity by inhalation route: no data available.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

625 mg/kg bw

Quality of whole database:

Two studies were available with good reliability (Kr. 2). The tests were performed in compliance with international guidance requirements with acceptable restrictions.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Key study performed according to the 0ECD 402 guideline study and in compliance with the GLP (Klimisch score = 1).

Additional information

1- Acute oral toxicity:

Two studies were available with reliability 2 according to Klimisch rating (Kr).

- A study report (SPL, 1991) has been chosen as key study for this endpoint. This study was conducted according to OECD guideline 401 and in compliance with GLP. Groups of Sprague-Dawley rats (5/sex/group) were administered by gavage a single dose of a water solution of the registered substance (THPC-urea) (around 65% active ingredient – AI) at doses of 325, 650 and 1300 mg AI/kg and observed for 14 days. Hunched posture, ataxia, lethargy, ptosis, laboured respiration, piloerection, dehydratation, and occasional body tremors were observed. At necropsy, abnormalities were observed in the liver, lungs, kidneys, stomach and gastrointestinal tract. Oral LD50 Female = 650 mg AI/kg (410 -1027), Oral LD50 Male = 606 mg AI/kg (431 - 851) and Oral LD50 Combined Males/Females = 625 mg AI/kg (477 -820)

- A study report (SPL, 1991) has been chosen as supporting study. Groups of Sprague-Dawley rats (five males and five females) were given a single oral dose of a diluted THPC-urea solution (around 32.5% AI) at doses of 162, 325 and 650 mg AI/kg bw and observed for 14 days. As in the key study, Signs of intoxication were hunched posture, ataxia, lethargy, ptosis, laboured respiration, piloerection, dehydratation, and occasional body tremors and at necropsy, abnormalities were observed in the liver, lungs, kidneys, stomach and gastrointestinal tract.

The LD50 values were approximately 580, 730 and 650 mg AI/kg for males, females, and males plus females respectively.

Taken these results together, THPC-urea is considered as harmful if swallowed according to EU criteria.

 

2- Acute dermal toxicity:

One study is available for this endpoint and considered as the key study (SPL, 1994). This study was conducted according to OECD guideline 402 and in compliance with GLP (Kr: 1). Groups of Sprague-Dawley rats (5/sex/group) were dermally exposed to a water solution of THPC-urea (around 65% Active Ingredient – AI) at a limit dose level of 2000 mg test material/kg bw (equivalent to 1306 mg AI/kg bw) and observed for 14 days. There were no deaths. Signs of toxicity or skin irritation disappear before the end of the 14 -day observation period. All animals showed expected gain in body weight, except for 2 females which showed body weight loss during the first week of the study. No abnormalities were noted at necropsy.The dermal LD50 combined of THPC-urea was estimated to be greater than 1306 mg AI/kg bw, without neither deaths nor systemic effects observed during the study period. Thus the registered substance is considered as not harmful by dermal route according to EU criteria.

 

3- Acute inhalation toxicity: No data was available.

Justification for selection of acute toxicity – oral endpoint
Key study performed according to the 0ECD 401 guideline study and in compliance with the GLP (Klimisch score = 2). Furthermore, in the supporting study LD50 for female and combined sexes have been extrapolated

Justification for selection of acute toxicity – inhalation endpoint
Waiving based on the corrosive properties of the submitted substance.

Justification for selection of acute toxicity – dermal endpoint
Only one study was available.

Justification for classification or non-classification

1- Acute oral toxicity:

Based on LD50 Combined Males/Females = 625 mg AI/kg from Kr 2 study according to OECD 401.

THPC-urea is classified in category 4, H302 according to the CLP regulation (1272/2008) and as harmful if swallowed (Xn; R22) according to the Directive 67/548/EEC criteria.

 

2- Acute dermal toxicity:

Not classified according to the EU legislation (Directive 67/548/EEC and CLP regulation (1272/2008)) as the dermal LD50 combined of THPC-urea was found to be greater than 1306 mg AI/kg bw without neither deaths nor systemic effects observed during the study period

3- Acute inhalation toxicity:

No classification is possible due to lack of data.