Calcium cyanamide

Other distribution data

Administrative data

Endpoint:

other distribution data

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: BBA Guideline for the Testing of Plant Protection Products (Part IV-4-3: Lysimeteruntersuchungen zur Verlagerung von Pflanzenschutzmitteln in den Untergrund

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

soil leaching

Media:

other: soil

Test material

Test material information

Constituent 1

Reference substance name:

Calcium cyanamide

EC Number:

205-861-8

EC Name:

Calcium cyanamide

Cas Number:

156-62-7

Molecular formula:

CN2.Ca

IUPAC Name:

calcium cyanoazanediide

impurity 1

Reference substance name:

Carbon

EC Number:

231-153-3

EC Name:

Carbon

Cas Number:

7440-44-0

Molecular formula:

C

IUPAC Name:

carbon

impurity 2

Reference substance name:

Hematite (Fe2O3)

EC Number:

215-275-4

EC Name:

Hematite (Fe2O3)

Cas Number:

1317-60-8

Molecular formula:

Fe2O3

IUPAC Name:

diiron oxide

impurity 3

Reference substance name:

Urea

EC Number:

200-315-5

EC Name:

Urea

Cas Number:

57-13-6

Molecular formula:

CH4N2O

IUPAC Name:

urea

impurity 4

Reference substance name:

Silicon dioxide

EC Number:

231-545-4

EC Name:

Silicon dioxide

Cas Number:

7631-86-9

Molecular formula:

O2Si

IUPAC Name:

dioxosilane

impurity 5

Reference substance name:

Calcium dihydroxide

EC Number:

215-137-3

EC Name:

Calcium dihydroxide

Cas Number:

1305-62-0

Molecular formula:

CaH2O2

IUPAC Name:

calcium dihydroxide

impurity 6

Reference substance name:

Aluminium oxide

EC Number:

215-691-6

EC Name:

Aluminium oxide

Cas Number:

1344-28-1

Molecular formula:

Al2O3

IUPAC Name:

aluminium oxide

impurity 7

Reference substance name:

Cyanoguanidine

EC Number:

207-312-8

EC Name:

Cyanoguanidine

Cas Number:

461-58-5

Molecular formula:

C2H4N4

IUPAC Name:

2-cyanoguanidine

impurity 8

Reference substance name:

Calcium sulfate

EC Number:

231-900-3

EC Name:

Calcium sulfate

Cas Number:

7778-18-9

Molecular formula:

CaH2O4S

IUPAC Name:

calcium sulfate

impurity 9

Reference substance name:

Calcium carbonate

EC Number:

207-439-9

EC Name:

Calcium carbonate

Cas Number:

471-34-1

Molecular formula:

CH2O3.Ca

IUPAC Name:

calcium carbonate

impurity 10

Reference substance name:

Calcium nitrate

EC Number:

233-332-1

EC Name:

Calcium nitrate

Cas Number:

10124-37-5

Molecular formula:

Ca.2HNO3

IUPAC Name:

calcium dinitrate

impurity 11

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Dihydrogen oxide

impurity 12

Reference substance name:

unknown

IUPAC Name:

unknown

Test material form:

solid: granular

Details on test material:

Calcium Cyanamide is sold under the name of PERLKA in granular form as fertiliser. For study purpose PERLKA granulate is grinded to powder.

Specific details on test material used for the study:

Charge 1402

Results and discussion

Any other information on results incl. tables

- PERLKA contains 42–46 % calcium cyanamide. Upon contact with water, calcium cyanamide is transformed into cyanamide (H2CN2) For this reason, studies with PERLKA can be used for assessing the risks related to the use of cyanamide

Cyanamide concentration in percolate:

1^styear: During the period of May 15, 1991 until November 18, 1991, the total volume of percolate was less than 3 l/lysimeter and did not allow to conduct any analytical investigation. Therefore, amounts with less than 3 l were put back through the suction tube into the percolate sampling chamber. Only at the first sampling date (December 2, 1991) a cyanamide concentration of 0.19 µg/L was determined in lysimeter L9. In lysimeter L10, the cyanamide concentration in the percolate was found to be 0.095 µg/L. In addition, in one replicate of samples from 20 January and 18 February 1992 small amount of 0.07 µg/L were detected whereas cyanamide concentration in the second replicate of the two dates were below the limit of quantification (LOQ = 0.06 µg/L). All following samplings in the first trial year did not disclose further cyanamide leaching.

The mean cyanamide concentration in the total percolate of the 1^st year was < 0.03 µg/L for both lysimeters.

2^ndyear: In the second year lysimeter 9 was treated again with PERLKA. Cyanamide was detected in the percolates sampled on 20 November and December 07, 1992 at concentrations of 0.13 µg/L and 0.11 µg/L, respectively. Based on the total volume of percolate in the second trial year, mean cyanamide concentration in the total percolate was < 0.03 µg/L for lysimeter L9. In lysimeter L10 which was not treated again in the 2^nd year no cyanamide was detected in any percolate sample.

3^rdyear: Cyanamide did not appear above the limit of quantification (LOQ = 0.06 µg/L) in any percolate sample of lysimeters L9 and L10.

 

Cyanamide concentration in soil:

The Cyanamide concentrations in all soil samples investigated were below the detection limit of 0.05 mg/kg soil.

Concentration of cyanamide in percolate after application of PERKLA - lysimeter L9:

Date of sampling	Percolate	Replicate	Cyanamide found [µg/L]	% of applied substance^1)
Dec 02, 91	25.0	1 2	0.18 0.20	£0.001 £0.001
Jan 06, 92	44.9	1/2	n.d.	n.d.
Jan 20, 92	17.9	1/2	n.d.	n.d.
Feb 18, 92	40.4	1/2	n.d.	n.d.
Mar 02, 92	19.0	1/2	n.d.	n.d.
Mar 16, 92	12.6	1/2	n.d.	n.d.
Apr 02, 92	39.3	1/2	n.d.	n.d.
TOTAL 1^styear	199.1	-	< 0.03
Sep 03, 92	3.1	1/2	n.d.	n.d.
Nov 05, 92	49.5	1/2	n.d.	n.d.
Nov 20,92	24.8	1/2	n.d. 0.13	n.d. £0.001
Dec 07, 92	31.1	1	0.11	£0.001
Dec 21, 92	12.7	1	n.d.	n.d.
Jan 04, 93	6.1	1	n.d.	n.d.
Jan19, 93	25.0	1	n.d.	n.d.
Feb 01, 93	8.7	1	n.d.	n.d.
Feb 16, 93	5.9	1	n.d.	n.d.
Mar 01, 93	23.9	1/2	n.d.	n.d.
Mar 16, 93	18.0	1/2	n.d.	n.d.
Apr 06, 93	17.8	1	n.d.	n.d.
Apr 19, 93	9.4	1	n.d.	n.d.
TOTAL 2^ndyear	236.0	-	< 0.03
TOTAL 3^rdyear	268.0		n.d.
^1)applied substance: 32 g PERLKA/lysimeter (14.82 g Cyanamide/lysimeter) = 100% n.d. not detected

Concentration of cyanamide in percolate after application of PERKLA - lysimeter L10:

Date of sampling	Percolate	Replicate	Cyanamide found [µg/L]	% of applied substance^1)
Dec 02, 91	4.4	1 2	0.09 0.10	£0.001 £0.001
Jan 06, 92	44.6	1/2	n.d.	n.d.
Jan 20, 92	15.5	1 2	0.07 n.d.	£0.001 n.d.
Feb 18, 92	40.2	1 2	0.07 n.d.	£0.001 n.d.
Mar 02, 92	19.6	1/2	n.d.	n.d.
Mar 16, 92	11.6	1/2	n.d.	n.d.
Apr 02, 92	38.9	1/2	n.d.	n.d.
TOTAL 1^styear	174.8	-	< 0.02	-
TOTAL 2^ndyear	202.6	-	n.d.	-
TOTAL 3^rdyear	258.6	-	n.d.	-
^1)applied substance: 32 g PERLKA/lysimeter (14.82 g Cyanamide/lysimeter) = 100% n.d. not detected

 

Applicant's summary and conclusion

Conclusions:

Results showed that preferential flow events occurred in the course of the experiment. The mean cyanamide concentrations in the total percolate of the 1st and 2nd year were < 0.03 µg/L. The cyanamide concentrations in all soil samples investigated were below the detection limit of 0.05 mg/kg soil.
Accordingly, it can be stated that complete degradation of cyanamide takes place after a PERKLA application. After repeated application no enrichment of cyanamide residues can be expected. The degradation of cyanamide in soil contributed to the finding that only traces of cyanamide appeared in the percolate after application of PERLKA.

Executive summary:

The percolation behaviour of calcium cyanamide, applied as formulated product PERLKA, was investigated in two lysimeters (L9 and L10) with undisturbed sandy loam soil monoliths. PERLKA contains 42–46 % calcium cyanamide. Upon contact with water, calcium cyanamide is transformed to cyanamide (H2CN2). The lysimeters were embedded into the ground to soil level surrounded by a small field plot, exposed to natural sunlight and precipitation. The surroundings of the two lysimeters were used as control area and planted with the same plants as the lysimeters. In the first year PERLKA was spread by hand to each lysimeter onto winter wheat at an amount of 32 g/lysimeter equivalent to 400 kg PERLKA/ha. The application rate corresponded to 94.3 kg cyanamide/ha. In the second year PERLKA was applied to lysimeter L9 on winter barley, spread by hand, at an application rate of 400 kg PERLKA/ha corresponding to 91.0 kg cyanamide/ha. Leachate samples were taken at intervals of 4 weeks (during summer) and 2 weeks (from autumn to spring). Soil samples were collected twice per year by removing three 30 × 4 cm soil columns from the soil using an “Humax” auger. The soil columns were fractionized into 0 10 cm, 10–20 cm and 20–30 cm layers. At the end of the experiment (1106 days after 1st application, 760days after 2nd application), the soil monoliths were sectioned into horizontal segments of about 10 cm thickness, which were analysed separately.

The percolate formation of both lysimeters was very similar during the three test years. During the 1st experimental year only traces of cyanamide appeared in the percolate samples shortly after beginning of the leaching period. These results were confirmed in the 2nd test year in two percolate samples of lysimeter L9 which was treated with PERLKA a second time. These single findings showed that preferential flow events occurred in the course of the experiment. The mean cyanamide concentrations in the total percolate of the 1st and 2nd years were < 0.03 µg/L. The cyanamide concentrations in all soil samples investigated were below the detection limit of 0.05 mg/kg soil.

It can be stated that complete degradation of calcium cyanamide takes place after a PERKLA application. After repeated application no enrichment of calcium cyanamide residues can be expected. The degradation of calcium cyanamide in soil contributed to the finding that only traces of calcium cyanamide appeared in the percolate after application of PERLKA.