Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
By inhalation
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
By inhalation
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
0.29 mg/m³
Most sensitive endpoint:
irritation (respiratory tract)
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
5
Dose descriptor:
NOAEC
Value:
1.46 mg/m³
AF for dose response relationship:
1
Justification:
The standard factor 1 is used, because the starting point is a NOAEC (see Chapter R.8.4.3.1 of TGD)
AF for differences in duration of exposure:
1
Justification:
The assessment factor suggested by the ECHA TGD for exposure duration from subchronic to chronic should be 2, but extrapolation factors for differences in duration of exposure are not always needed (according to ECHA Guidance R.8, page 29). In the depicted case only local effects (no systemic effects) were observed, and the 14-days repeated dose toxicity inhalation pre-study (Ma-Hock, 2009) leads to nearly the same result as the subchronic 90-days study (Ma-Hock, 2009) (NOAEC 5 mg/m3 versus 2.9 mg/m3; dose levels 5, 25, and 125 vs. 3, 15, and 75 mg/m3); the slight differences are due to dose selection. Similarily, the mid dose of the 14-day study and the 90-day study (i.e. 25 mg/m3 vs. 15 mg/m3, respectively) cause comparable respiratory irritant effects. Taking into account the variability of the biological system 25 vs. 15 mg/m3 is a very similar dose level. Also here the dose selection accounts for the slight difference (slightly lower doses were chosen for the 90-day study). Therefore it is not expected that a longer duration of the study would change the outcome and a AF of 1 is warranted.
AF for interspecies differences (allometric scaling):
1
Justification:
An allometric scaling factor is not applicable for local effects (see section R 8.4.3.1 of TGD), therefore AF 1 is chosen.
AF for other interspecies differences:
1
Justification:
A factor 2.5 is suggested by the ECHA TGD for remaining interspecies differences, but justified deviations are possible. The available repeated inhalation 90-day study with rats (Ma-Hock, 2009) with the substance gives proof that the local irritant effect at the port-of-entry/first site of contact (i.e. respiratory tract) is the toxicological Mode of Action (MoA). For local effects on the respiratory tract it should be taken into account that rodents like the rat are in general more sensitive compared to humans as the rat`s ventilation frequency is higher. Additionally, it is not indicated that humans are more susceptible against these kind of effects, therefore, a factor of 1 for remaining interspecies differences is applied and is considered to provide sufficient protection.
AF for intraspecies differences:
5
Justification:
For intraspecies variability, the default assessment factor for workers for local effects is 5 aacording to Chapter 8.4.3.1 of TGD.
AF for the quality of the whole database:
1
Justification:
Because of good/standard quality of the database the standard assessment factor 1 is used as decribed in chapter R 8.4.3.1 of TGD.
AF for remaining uncertainties:
1
Justification:
No further assessment factors are considered necessary.
Acute/short term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
0.58 mg/m³
Most sensitive endpoint:
irritation (respiratory tract)
DNEL related information
DNEL extrapolated from long term DNEL

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
repeated dose toxicity
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
Most sensitive endpoint:
sensitisation (skin)
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
medium hazard (no threshold derived)
Most sensitive endpoint:
sensitisation (skin)
Acute/short term exposure
Hazard assessment conclusion:
medium hazard (no threshold derived)
Most sensitive endpoint:
sensitisation (skin)

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - workers

For workers in industrial settings, which are exposed via inhalation, DNELs for acute and long-term inhalation effects of 3 -isocyanatomethyl-3,5,5 -trimethylcyclohexylisocyanate homopolymer, isocyanurate type (IPDI homopolymer) have to be derived. In addition, the sensitization potential after skin contact to IPDI homopolymer have to be assessed.

For repeated dose toxicity one subchronic inhalation study with dust exposure of IPDI homopolymer to rats is available (Ma-Hock, 2009). The obtained NOAEC and LOAEC were 2.9 mg/m3 and 15 mg/m3, respectively, for effects governed by respiratory tract irritation. No indications of systemic toxicity were found within this study. Therefore, 2.9 mg/m3 was used as a starting point for the delineation of a DNELlong-term for workers for inhalation route.

For acute dose toxicity two short term inhalation studies with aerosol exposure of IPDI homopolymer to rats are available (Bayer AG, 1996 and Pauluhn, 2003). In the first study an inhalative LC50 value of > 5010 mg/m3 was obtained. No mortalities were observed. The clinical observation demonstrate that the dust acts as mild respiratory tract irritant. Assessment of the acute inhalation toxicity data from the second study with rats (single 6 hours inhalation exposure) also indicates that the exposure of respirable aerosols of IPDI homopolymer causes irritation of the respiratory tract. No indications of systemic toxicity were found within these two studies.

For the short-term ceiling concentration an exposure limit has been etablished by multiplication the long-term ceiling concentration to an exceeding factor (see above). For 3 -isocyanatomethyl-3,5,5 -trimethylcyclohexylisocyanate homopolymer an exceeding factor of 2 is applied.

A dermal sensitization potential was shown for 3 -isocyanatomethyl-3,5,5 -trimethylcyclohexylisocyanate homopolymer (IPDI homopolymer) in two skin sensitization studies (Vohr, 2003 and NOTOX, 2004). According to the potency categorisation approach (Appendix R.8-10 of TGD) IPDI homopolymer is classified as a moderate skin sensitizer based on the Guinea Pig Maximization Test (50 % induction conc., >= 60 % incidence of sensitisation; NOTOX B.V., 2004). In consideration of risk management measures inhalation is the most probably route of exposure. Dermal exposure has to be avoided because of sensitizing properties of IPDI homopolymer.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - General Population

3 -Isocyanatomethyl-3,5,5 -trimethylcyclohexylisocyanate homopolymer, isocyanurate type (IPDI homopolymer) is exclusively used as intermediate in chemical processes (i.e. hardener for coating materials or adhesives for industrial and professional use). A direct use of this substance is not known. The exposure of consumers to IPDI homopolymer is unlikely to occur via consumer products, because no consumer product is known to contain the substance. An exposure of consumers or general population via the environment is also unlikely to occur, because there are no significant exposure from environmental sources, and IPDI homopolymer released to the environment would rapidly be degraded by water and photooxidants. Therefore, DNELs for consumers or general population are not applicable as consumers are not involved in the industrial or professional use of IPDI homopolymer or of preparations containing this substance. Additionally, in view of the lack of systemic toxicity in experimental studies and the lack of exposure from environment sources, the risk to the general population has been minimized. A Developmental Toxicity Study with repeated oral administration of the test substance (LPT, 2017) revealed no test item-related findings at all. This gives further proof that administration of the test substance, even after repreated doses up to 1000 mg/kg bw does not lead to systemic toxicity and thus systemic availability is expected to be low after oral exposure.