Cyanamide

Storage stability and reactivity towards container material

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

storage stability and reactivity towards container material

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2005-09-16/ 2006-05-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: Dangerous goods regulations

Deviations:

not specified

GLP compliance:

not specified

Type of method:

other: Stability under storage conditions for different period of time (until 360 days)

Results:

Storage conditions: 360 days at 20 °C
Production of dicyandiamide: 0.5 to 0.7 %

Storage conditions: 90 days at 20 °C
Production of dicyandiamide: 0.5 to 0.7 %

Storage conditions: 14 days at 20 °C
Production of dicyandiamide: 0.5 to 0.7 %

Transformation products:

yes

No.:

#1

Storage stability / reactivity towards container material:

other: Cyanamide F 1000 has a an excellent long-run stability

- Stabilization effect (explanation for the expected stability of Cyanamid F1000): The task of stabilizator of solid cyanamide consists in preventing the production of alkaline substances, which catalyze the dimerization, as well as in absorbing of moisture that might cause a hydration of cyanamide. The stabilization of Cyanamid F1000 is carried out in two ways. On the one hand Cyanamid F1000 is produced by gentle evaporation of the formulation Cyanamid L500, which had been stabilized by phosphate. The adherent parts of phosphate of the crystalline product nsure a sufficient stabilization for the following drying as well as for the in-house handling. After the drying an “extra stabilizer” is added to Cyanamid F1000 before the product will be placed into circulation. This proprietary formic acid ester has the function to absorb fraces of moisture, to neutralize alkaline traces (NH3) as well as to release continuously small amounts of formic acid

 

- Following the results presented above and as a routine, each charge destined for shipment has to undergo a quick test to eliminate any error in the manufacturing process that might have an effect on the stability of Cyanamid F1000. In this test a sample of 50 g is stored during 24 hours at 60 °C (i.e. in the molten state. Then the increase of the concentration of dicyandiamide is measured. A shipment is possible only, if the limit of a maximum increase of dicyandiamide of 3.0 % is not exceeded. Experiences of many years show that the measured values are mostly far below the limiting value.

 

- In addition other test results were obtained which assisted in concluding a storage and transport regulation for Cyanamid F1000: Following results of the UN tests (A.1, C.1, C.2, E.1, E.2, E.3, F.3), Cyanamid F1000 is not flammable, not explosive, and not a self reactive substance of class 4.1 of the dangerous goods regulations. The performed tests also assisted in determination of the SADT (self-accelerating decomposition temperature) relating to containers of 50 kg lead the BAM to the conclusion that for containers with a content of 50 kg a 50 °C is adequate and during transport 40 °C.

Conclusions:

F 1000 has a long-run stability.

Executive summary:

The BAM presented an expert opinion on classification and assignment of Cyanamide F 1000 according to the UN dangerous goods regulations. Following a theoretical biochemical analysis predicting the stability of Cyanamide F 1000, results of an isothermal storage test were presented, in which the production of dicyandiamide as function of storage conditions (days and temperatures) was presented. These results showed that Cyanamide F 1000 has a long-run stability. In addition other results according to the test methods for self-reactive substances of the UN Manual of Tests and criteria of dangerous goods, completed the conclusion presenting Cyanamide F 1000 as stable, not a self-reactive substance and readily available for storage or transport at a mass of 50 kg at 40 °C or 50 °C, respectively.

Reference 2

Endpoint:

storage stability and reactivity towards container material

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 830.6313 (Storage Stability)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ADR (Accord europeen relatif au transport international des marchandises dangereuses par route) under the aegis of the United Nations Economic Commission for Europe, amended April 1985 and January 2009 as document ECE/TRANS/202 Vol. I and II (ADR 2009)

Deviations:

no

GLP compliance:

not specified

Type of method:

testing for reactivity towards container material

Specific details on test material used for the study:

A round bottom flask filled with around 300 mL Cyanamid L500 P stabilised with phosphoric acid contained a piece (coupon) of metal, steel, which was completely covered by the cyanamide solution. The steel corrosion test lasted 15 days. During the test the cyanamide solution was kept at a temperature of 55 °C. The cyanamide solution was changed to a fresh solution once a day during the steel study.
The metal coupon was weighed and optically examined before and after the test.

Results:

Weight of the metal coupon before the test and after respectively: 11.1186 g, 11.0932 g
Corrosion rate: - 0.11 mm/p.a
Appearance: No significant changes

Transformation products:

no

Storage stability / reactivity towards container material:

other: Not corrosive to containers made of aluminium or steel.

The steel corrosion test result showed a corrosion rate of 0.11 mm/p.a towards exposure to cyanamide solution, which is in a factor of 57 under the classification limit (a classification rate of 6.25 according to the ADR/Klasse 8).

Conclusions:

Under the conditions of the study, Cyanamid L500 was found to be not corrosive steel.

Executive summary:

In the presented study the possible corrosivity of a container metal, steel, as a result of exposure to cyanamide (50 % technical cyanamide solution) was examined.

A round bottom flask filled with around 300 mL Cyanamid L500 P stabilised with phosphoric acid contained a piece (coupon) of metal, steel, which was completely covered by the cyanamide solution. The steel corrosion test lasted 15 days.

During the test the cyanamide solution was kept at a temperature of 55 °C. The cyanamide solution was changed to a fresh solution once a day during the study.

The steel coupon was weighed and optically examined before and after the test.

The corrosion test result showed a corrosion rate of 0.11 mm/p.a of aluminium towards exposure to cyanamide solution, which is in a factor of 57 under the classification limit (a classification limit of 6.25 according to the ADR/Klasse 8). No changes in weight or appearance were observed.

It can be concluded that under the test conditions the test item is not corrosive to steel.

Reference 3

Endpoint:

storage stability and reactivity towards container material

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 830.6313 (Storage Stability)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ADR (Accord europeen relatif au transport international des marchandises dangereuses par route) under the aegis of the United Nations Economic Commission for Europe, amended April 1985 and January 2009 as document ECE/TRANS/202 Vol. I and II (ADR 2009)

Deviations:

no

GLP compliance:

not specified

Type of method:

testing for reactivity towards container material

Specific details on test material used for the study:

A round bottom flask filled with around 300 mL Cyanamid L500 A stabilised with formic acid contained a piece (coupon) of metal, aluminium, which was completely covered by the cyanamide solution. The aluminium corrosion test lasted 30 days. During the test the cyanamide solution was kept at a temperature of 55 °C and was changed to a fresh solution 3 times in per week. The metal coupon was weighed and optically examined before and after the test.

Results:

Aluminium corrosion test with cyanamide
Weight of the metal coupon before the test and after respectively: 8.0024 g, 7.9869 g
Corrosion rate: - 0.055 mm/p.a (-2.21 % p.a)
Appearance: No change of the surface area. In the cutting area a localised corrosion was observed.

Transformation products:

no

Storage stability / reactivity towards container material:

other: Not corrosive to containers made of aluminium or steel.

The aluminium corrosion test result showed a corrosion rate of 0.055 mm/p.a after exposure to cyanamide solution, which is in a factor of 114 under the classification limit (classification limit of 6.25, according to the ADR/Klasse 8).

Conclusions:

Under the conditions of the study, Cyanamid L500 was found to be not corrosive to aluminium.

Executive summary:

In the presented study the possible corrosivity of a container metal, aluminium towars exposure to cyanamide (50 % technical cyanamide solution) was examined.

A round bottom flask filled with around 300 mL Cyanamid L500 A, stabilised with formic acid contained a piece (coupon) of metal, aluminium, which was completely covered by the cyanamide solution. The aluminium corrosion test lasted 30 days. During the test the cyanamide solution was kept at a temperature of 55 °C. The cyanamide solution was changed to a fresh solution 3 times in a week during the study. The metal coupon was weighed and optically examined before and after the test.

The aluminium corrosion test result showed a corrosion rate of 0.055 mm/p.a towards exposure to cyanamide solution, which is in a factor of 114 under the classification limit (classification rate of 6.25 according to the ADR/Klasse 8). No weight change and no change of the surface area was observed. In the cutting area only a localised corrosion was observed.

It can be concluded that under the test conditions the test item is not corrosive to aluminium.

Description of key information

Cyanamid L500 was proved to be not corrosive to aluminium and steel. An isothermal storage test showed that Cyanamid F1000 has a long-run stability, supported by the classification of Cyanamid F1000 as a not self-reactive substance. It was also concluded that the Cyanamid F1000 should be available for storage or transport at a mass of 50 kg at 40 °C or 50 °C, respectively.

Additional information

Results of a 30 days aluminium corrosion test with the test substance Cyanamid L500 (stabilised with formic acid) and results of a 15 days steel corrosion test with Cyanamid L500 (stabilised with phosphoric acid) performed at 55 °C, showed that the test substance is not corrosive to aluminium and steel.

The BAM presented an expert opinion on classification and assignment of Cyanamid F1000 according to the UN dangerous goods regulations. Results of an isothermal storage test were presented, in which the production of dicyandiamide as a function of storage conditions (days and temperatures) was examined. These results showed that Cyanamid F1000 has a long-run stability. In addition other results according to the test methods for self-reactive substances of the UN Manual of Tests and criteria of dangerous goods, completed the conclusion presenting Cyanamid F1000 as stable, not a self-reactive substance and readily available for storage or transport at a mass of 50 kg at 40 °C or 50 °C, respectively.