Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 700-990-0
CAS number: -
90-day oral toxicity study in rat (equivalent or similar to OECD408):- NOAEL: (M) 107.5 mg/kg bw/day, (F) 124.8 mg/kg bw/day (highest doses tested)21-day dermal toxicity in rabbit (equivalent or similar to OECD410):- NOAEL: 10 mg/kg bw/day
In the key study for the oral route, Phosflex 51B was administered to
rats in the diet. No treatment related mortality and clinical signs were
noted in the animals. The statistically significant differences in
hematology and clinical chemistry values and in red blood cell, plasma
and brain cholinesterase activities between control and treated animals
were minimal, inconsistent and considered not to be of biological
significance. A biologically significant increase in liver and adrenal
weights (only females) was noted in the high-dose groups, but this was
not regarded as a toxic and therefore not an adverse effect. A NOAEL of
107.5 and 124.8 mg/kg bw/day (equivalent to 1600 ppm) was established
for males and females, respectively.
Two supporting studies for the oral route were available: a 28-day and a
90-day toxicity study in rats. The subacute toxicity study (equivalent
of established a NOAEL of 250 mg/kg bw/day based on liver effects in all
dose groups, except for the lowest dose group. The 90-day toxicity study
established a NOAEL of 71.6 mg/kg bw/day and 86.2 mg/kg bw/day for male
and female, respectively, based on the absence of effects at the highest
dose. The key study was chosen as such as it was performed using the
most relevant exposure route (oral versus inhalation), a treatment
period of 90 days (as compared to 28-days in the supporting study with a
higher NOAEL) and it tested the highest concentration at which no
adverse effects were observed (as compared to the other 90-day oral
Two subacute repeated dose toxicity studies for the dermal route are
available. In the key study, rabbits were exposed to tBuTPP for 21 days.
An evident dose response depression of terminal cholinesterase was
observed in the treated males and females, which was significant in the
mid and high dose, a NOAEL of 10 mg/kg bw/day was derived. This finding
was supported by a second 21 -day study in rabbits, in which a LOAEL of
100 mg/kg bw/day was observed based on the same effects. As in the 90
-day oral repeated dose toxicity study, significant effects on
cholinesterase were noted at the interim measurement after 45 days of
exposure, but these effects were minimal and considered not to be of
biological significance after the end of treatment (90 days), the NOAEL
from this study was used as key value for derivation of the DNEL.
Additionally a 90-day inhalation toxicity study in rats was available
that established a NOAEL of 101.1 mg/m3 based on the absence of effects
at this dose (highest tested). As no effects were observed at the
highest dose, it was decided to use the NOAEL from the oral 90 -day
study as key value for derivation of the DNEL.
The most critical NOAEL established for t-BuTPP was 107.5 mg/kg bw/day.
When considering the guidance values for classification as outlined in
Annex I of 1272/2008/EC (significant effect observed at 100 mg/kg
bw/day) and Annex VI of 67/548/EEC (significant effect observed at 50
mg/kg bw/day), the substance does not need to be classified for repeated
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again