2,2'-iminobis[4,6-diamino-1,3,5-triazine]

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

repeated dose toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

melam

IUPAC Name:

melam

Results and discussion

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Executive summary:

No toxicity at all and especially also no systemic toxicity was detected in the repeated dose oral toxicity study even at the high dose of 1000 mg/kg bw.

Melam is not irritant to eyes and skin, and it can be expected therefore that no local but - if any - systemic toxic effects would occur at inhalation exposure. The stability of melam is high, even higher than that of the related substance melamine, and it can be assumed, as with melamine, that no metabolism of melam in the organism and by this no first pass effect occurs. It is therefore expected that the toxic effects after oral and inhalation exposure would be qualitatively the same.

No difference in the toxicity was noted between the acute oral toxicity studies and the acute inhalation toxicity studies as no toxicity was detected at all in both routes.

It is concluded that no toxicity will be revealed in the inhalation repeated dose study too, especially at low exposures as it is expected for humans.

Low exposure: The exposure of humans will be low, as the conditions during manufacturing will prevent an exposure to dust. Melam is exclusively introduced into plastic material during compounding. It is included by this process into a matrix and is no longer available for inhalation or dermal exposure. Melam is used for electronic components in Personal Computers, Televisions, Laptops etc. There is no direct contact by hands touching the components. So the only exposure might be inhalation of vapour, escaping from the electronic components. The vapour pressure of melam is very low and only insignificant exposures are expected from this source.

The following argumentations were taken from the paper "Maximum expected exposure levels in workers and the general population" of T. Tiemersma and Wil ten Berge of DSM Regulatory Affairs & Product Safety Polymers, 6 July 2010, report Tox. 31490a. "Melam is a solid. For solids exist a general exposure level to prevent irritation of the respiratory tract, that is 10 mg/m3 for inhalable dust and 3 mg/m3 for respirable particles. Commercial melam consists for about 30 % of respirable particles. Respirable particles remain longer airborne and the total concentration will normally be lower than 10 mg/m3, if the respirable particles should not exceed 3 mg/m3 (ACGIH). Respirable particles that are retained in the respiratory tract, will be dissolved in the aqueous mucous layer and mainly absorbed by secondary ingestion. It is assumed that a worker inhales 10 m3 of air during a working day and that the average bodyweight of the worker is 70 kg. At an average concentration of 10 mg melam per m3 the worker inhales 100 mg/day or 1.43 mg/kg bw/day.

The exposure of consumers should be related to the end use of melam. Melam is used for electronic components in Personal Computers, Televisions, Laptops etc. There is no direct contact by hands touching the components. So the only exposure might be inhalation of vapour, escaping from the electronic components. The highest estimated vapour pressure (an overestimation compared to AC-labs) appears to be 5.2 E-8 Pascal related to pure melam. So an atmosphere saturated with pure melam vapour, contains 5 ng per m3. Due to limited mass transfer (mixed in electronic component material) to the atmosphere, the expected exposure value might be 100 times lower. It is unimaginable, that melam would do any harm to the consumer by inhalation exposure. The inhaled daily dose per day for a consumer is 0.014 nanogram per kgbw/day."