2-piperazin-1-ylethanol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Exposure based adaptation of information requirements:

According to REGULATION (EC) No 1907/2006, Annex IX and Annex X, repeated dose/reproduction toxicity testing (section 8.6/section 8.7) may be omitted, if relevant human exposure can be excluded in accordance with Annex XI section 3. Furthermore and in accordance with section 3.2 (b) of Annex XI (as amended by Regulation 134/2009), testing for repeated dose toxicity/reproduction toxicity can be omitted when the substance is not incorporated in an article and the manufacturer can demonstrate and document for all relevant scenarios that throughout the life cycle strictly controlled as well as rigorously contained conditions as set out in Article 18(4)(a) to (f) (Regulation 1907/2006) apply.

 

Life-cycle stage(s) covered:

1. Production of Hydroxyethylpiperazine (PROCs 1, 2, 3, 8b, 15)

2. Formulation of Hydroxyethylpiperazine into a mixture (PROCs 1, 2, 3)

3. Use of Hydroxyethylpiperazine in gas treatment (PROCs 1, 2, 3)

4. Intermediate use (PROCs 1, 2, 3, 15)

 

Classification:

H315: Causes skin irritation.

H318: Causes serious eye damage.

 

The substance is considered as corrosive to the eyes and capable of causing skin irritating effects. Based on the bacterial reverse mutation assay, the HPRT assay, and the CA test the test substance is not considered to induce gene mutations neither in the absence nor in the presence of a metabolic activation system.

 

 

1.    Process description: PRODUCTION

Piperazine solution and ethylenoxide are transferred via closed pipelines to the reactor. After the flow and temperature controlled reaction is completed, the produced crude hydroxyethylpiperazine (HEP) is transferred via a closed pipeline to the distillation column. Sampling is done with a closed system.

The whole process is operated discontinuously at elevated temperature. The reactor is located indoors. Due to the closed system, exposure to workers will not take place under normal operation conditions.

In the distillation process the crude HEP is separated in 3 fractions: light boiler, intermediate fraction and the pure fraction. The residue remains in the distillation vessel. The pure product is pumped from the vessel via a closed pipeline to the drum filling station.

Transfers, storage tank, reactor, processing equipment and feeds are operated in fully closed systems. Exposure is limited to occasional sampling tasks for quality control under strictly control conditions. Only a small, well-defined and trained group of workers is exposed occasionally to low levels using appropriate risk management measures to minimize exposure.

 

2.    Process description GAS TREATMENT:

The Feed Gas enters the Absorber at the bottom. The lean solution is fed at the top of the absorber and hence the liquid and the gas are getting in contact in a counter-current flow. The mass and heat exchange is performed in the packing sections installed in the absorber. The Treated Gas leaves the Absorber with a CO2 concentration < 2% as desired, to the pipeline or for further processing. The rich solution from the bottom of the absorber is fed to the HP flash vessel, operated at a pressure level between absorber pressure and Stripper pressure. A level control valve is used to reduce the pressure of the rich solution from the level of the absorber to the level of the HP flash. The Flash Gas from the HP flash vessel contains the major part of the dissolved inert gases, i.e. non-acid gases like methane, and a minor part of the acid gas. The solution is heated up in the heat exchanger whereby a smaller amount of gas might be released from the solution. A larger amount of gas is released after the solution has passed the let-down valve, which controls the level in the HP flash vessel. The solution is then flashed at the top of the Stripper where vapor and liquid separate. Most of the absorbed CO2 and H2S is stripped off by steam generated in the reboiler. The regenerated solution leaves the stripper bottom with only a very low residual acid gas loading. The heat from this stream is partly recovered in the heat exchanger. The Stripper vessel is furnished with a packed bed in order to provide a large surface area required to release the CO2. The lean solution is then cooled down further in the lean solution cooler and fed to the top of the lean absorber. A reflux condenser is installed on top of the Stripper vessel for cooling down the released acid gas and condensing a part of the steam. The remaining gas stream with the major part of the acid gas (Acid Off-Gas) leaves the condenser for downstream processing. The condensate is pumped back to the top of the Stripper vessel. An appropriate amount of water is fed to the unit for balancing the amount of vapor leaving the unit with the gas streams.

All vessels, pumps, heat exchangers, processing equipment and feeds are operated in fully closed systems. Exposure is limited to occasional sampling and shutdown tasks for quality control under strictly control conditions. Only a small, well-defined and trained group of workers is exposed occasionally to low levels using appropriate risk management measures to minimize exposure.

The whole process is operated continuously at elevated temperature and pressure. All vessels are located outdoors. Due to the closed system, exposure to workers will not take place under normal operation conditions.

 

Rigorous containment measures:

The substance is manufactured and used under strictly controlled conditions over the entire lifecycle. Exposure is limited to occasional sampling tasks for quality control, as well as to charging and discharging processes. Transport, storage tanks, reactors, processing equipment, and feeds operate in fully closed systems.

 

Procedural and control technologies are used to minimize residual emissions/exposure as well as qualitative risk considerations:

Operational and technical conditions and measures affecting and controlling workers exposure, such as local exhaust ventilation as well as personal protective equipment, such as goggles, chemically resistant gloves, and respiratory protection where potential exposure may occur as reported in the CSR are followed (see chapters 9 &10).

On the basis of the described process conditions, testing of Repeated Dose Toxicity (OECD TG 407) as well as Reproductive Toxicity (OECD TG 421 or 422) was not performed since the criteria of exposure based adaptation of information requirements are met.

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Effects on developmental toxicity

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Mode of Action Analysis / Human Relevance Framework

No further information available.