Calcium cyanamide

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Justification for read-across for ecotoxicological endpoints:
Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved, calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar both in chemical structure and regarding fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.
For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

Species:

Brassica rapa

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot dry mass

Species:

Brassica rapa

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot fresh mass

Species:

Brassica rapa

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: fresh mass of inflorescences /seed pods

Species:

Brassica rapa

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: dry mass of inflorecences / seed pods

Species:

Brassica rapa

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: number of inflorescences /seed pods

Species:

Brassica rapa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot fresh mass

Species:

Brassica rapa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: number of inflorescences/flowers

Species:

Avena sativa

Duration:

39 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot fresh mass

Species:

Avena sativa

Duration:

39 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot dry mass

Species:

Avena sativa

Duration:

39 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: fresh mass of inforescences / seed pods

Species:

Avena sativa

Duration:

39 d

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: dry mass of inflorecences /seed pods

Species:

Avena sativa

Duration:

39 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: number of inflorescences / seed pods

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot fresh mass

Details on results:

PHYTOTOXICITY RATING SYSTEM:
Avena sativa and Brassica rapa: Until the end of the test no plant had died nor exhibited visible phytotoxic effects such as e.g. chlorosis, necrosis, wilting, leaf and stem deformations greater than normal variation in growth and morphology.

Results with reference substance (positive control):

A test with a reference substance was not performed

Reported statistics and error estimates:

The R/S test was used to check normal distribution. Homogeneity of the variances was analysed using the Cochran´s test. To determine the No Observed Effect Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC) a Williams’ test (p<0.05, two sided) or, if homogeneity of variance was denied, a Bonferroni-Welch t-test was performed.
All statistical evaluations were performed using the ToxRat software Version 2.09 (ToxRat Solutions GmbH, 2006).

Figures for emergence rates and figures for shoot fresh and dry mass, number of inflorescences, inflorescences fresh and dry mass, number of flowers, number of seed pods, seed pods fresh and dry mass are presented in tables 2 - 5 in the attached document.

A summary of NOEC values is given in table 6 (please see attachment).

ECx values and a resulting dose-response curve could not be computed due to a lack of a dose-response relationship.

Other effects were not observed.

Validity criteria fulfilled:

yes

Conclusions:

Due to a lack of a dose-response relationship between the test item concentrations and the observed effects on the respective endpoints, ECx values could not be calculated. The EC50, however, can nevertheless to be deduced to be >100 mg a.s./kg soil dry mass.
The test item did not reduce the biomass or number of inflorescences or seed pods at any of the tested concentrations up to and including 100 mg a.s./kg soil dry mass for either of the two test species, B. rapa and A. sativa.

Based on the assumption that only a reduction in biomass or number of flowers/seed pods is an ecological adverse effect, the no observed adverse effect concentration (NOAEC) derived from the chronic plant test is ≥100 mg a.s./kg soil dry mass.

Justification for read-across for ecotoxicological endpoints:
Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved, calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar both in chemical structure and regarding fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.
For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

Materials and methods:

Seedling emergence, growth and reproduction were analysed on the two species Avena sativa and Brassica rapa according to ISO 22030 (2005): "Soil Quality – Biological methods – Chronic Toxicity in Higher Plants".

Results and discussion:

The validity criteria defined by the guideline have been fulfilled.

- The seedling emergence is at least 75% (mean value of all replicates): yes, the emergence rate was 100% for both species

- Healthy plants developed: Plants did not show poor growth or etiolate and flowers appeared during the first three weeks (rapid cycling B. rapa) or eight weeks, respectively (A. sativa): yes

- No more than one plant per vessel died during the test: yes, none of the plants died

Emergence rates of A. sativa and B. rapa for all treatments and for the control were ≥ 96% and ≥ 98%, respectively. No plant died during the test and no plant exhibited visible phytotoxic effects greater than normal variation in growth and morphology.

Shoot fresh mass of A. sativa on day 14 was significantly increased at 100 mg a.s./kg soil dry mass (dm). The NOEC was 50 mg a.s./kg soil dm.

On day 39 the number of inflorescences of A. sativa was significantly increased at 100 mg a.s./kg soil dm. The fresh mass of inflorescences was significantly increased at 100 mg a.s./kg soil dm. Shoot biomass (fresh and dry) was significantly increased at 100 mg a.s./kg soil dm.

For A. sativa, the lowest NOEC was 50 mg a.s./kg soil dm (increase of shoot fresh mass on day 14 and day 39).

ECx values could not be computed due to a lack of a dose-response relationship, the EC50, however, appears to be > 100 mg a.s./kg soil dry mass.

Shoot fresh mass of B. rapa on day 14 of the test was significantly increased compared to the control in treatment 100 mg a.s./kg soil dm. NOECs for shoot fresh mass and number of flowers were 50 mg and ≥ 100 mg a.s./kg soil dm, respectively.

On day 28 shoot dry weight of B. rapa was significantly increased at 100 mg a.s./kg soil dm. No effects were observed for shoot fresh weight, and for the fresh and dry weight of seed pods of B. rapa.

The lowest NOEC for B. rapa was 50 mg a.s./kg soil (increase of shoot fresh weight on day 14 and dry weight on day 28).

ECx values could not be computed due to a lack of a dose-response relationship, the EC50, however, can nevertheless to be deduced to be > 100 mg a.s./kg soil dry mass.

Based on the assumption that only a reduction in biomass or number of flowers/seed pods is an ecological adverse effect, the no observed adverse effect concentration (NOAEC) derived from the chronic plant test is ≥ 100 mg a.s./kg soil dry mass.

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Justification for read-across for ecotoxicological endpoints:
Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved, calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar both in chemical structure and regarding fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.
For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

Key result

Species:

Allium cepa

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

1.722 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Remarks on result:

other: The most sensitive plant was Allium cepa, therefore this result is presented in the results field

Key result

Species:

Allium cepa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

< 0.125 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

32 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Brassica oleracea var. capitata

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

< 0.125 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Lycopersicon esculentum

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

8 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Cucumis sativus

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

2 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

8 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Daucus carota

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

0.5 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Zea mays

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

32 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Lolium perenne

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

32 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Details on results:

The most sensitive endpoint in this study was shoot dry weight. The most sensitive plant was Allium cepa with an EC50 value of 1.722 kg cyanamide L 500/ha when applied directly to the soil.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Effects of Cyanamide L 500 on seedling emergence following a soil surface application:

Plant	Genus (Species)	NOEC (kg/ha)	EC50 (kg/ha)	Most sensitive parameter
Monocotyledone
Corn	Zea mays	32	> 32^a	Shoot dry weight as well as shoot height
Oat	Avena sativa	32	> 32^a	Shoot dry weight as well as shoot height
Onion	Allium cepa	<0.125	1.722	Shoot dry weight
Perennial rye grass	Lolium perenne	32	> 32^a	Shoot dry weight
Dicotyledone
Cabbage	Brassica oleracea	<0.125	6.08	Shoot dry weight
Carrot	Daucus carota	0.5	>32	Shoot height
Cucumber	Cucumis sativus	2	>32	Shoot height
Lettuce	Lactuca sativa	8	>32	Shoot dry weight
Tomato	Lycopersicon esculentum	8	18.42	Shoot dry weight

Validity criteria fulfilled:

yes

Conclusions:

The most sensitive endpoint in this study was shoot dry weight. The most sensitive plant was Allium cepa with an EC50 value of 1.722 kg cyanamide L 500/ha when applied directly to the soil and a NOEC of <0.125 kg cyanamide L 500/ha.

Justification for read-across for ecotoxicological endpoints:
Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved, calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar both in chemical structure and regarding fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.
For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

The study was conducted following the accepted test guideline OPPTS 850.4250 (1996): Seedling emergence Tier II and in accordance with GLP

Non-target terrestrial plant response to formulated cyanamide product, a 50.6 % (w/w) aqueous solution of cyanamide, was evaluated on 9 common plant species at the following dose levels: 0.125, 0.5, 2.0, 8.0 and 32.0 kg cyanamide L 500/ha, corresponding to 0.063, 0.253, 1.01, 4.05 and 16.19 kg ai/ha.

Effects on seedling emergence and early growth following soil surface application were assessed. The most sensitive endpoint in this study was shoot dry weight. The most sensitive plant was Allium cepa with an EC50 value of 1.722 kg cyanamide L 500/ha when applied directly to the soil and a NOEC of <0.125 kg cyanamide L 500/ha.

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reference 3

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

Justification for read-across for ecotoxicological endpoints:
Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved, calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar both in chemical structure and regarding fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.
For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Reason / purpose for cross-reference:

read-across source

GLP compliance:

yes (incl. QA statement)

Key result

Species:

Lycopersicon esculentum

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

33.2 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight and shoot height

Remarks on result:

other: The most sensitive plant was Lycopersicon esculentum, therefore this result is presented in the results field

Key result

Species:

Lycopersicon esculentum

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

< 2 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Cucumis sativus

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

4 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

8 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Zea mays

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

16 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Brassica oleracea var. capitata

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

32 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Species:

Allium cepa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

16 kg/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot dry weight

Details on results:

The most sensitive endpoint in this study was shoot dry weight for all species. The most sensitive species tested was tomato (Lycopersicon esculentum). The EC50-value for tomato is about 33.2 kg Cyanamid L500/ha which is far above the maximum recommended application rate of 20 kg Cyanamid L500/ha.

Results with reference substance (positive control):

No positive control

Reported statistics and error estimates:

Not indicated

Effects of Cyanamid L500 on vegetative vigour (foliar application): Shoot dry weight

Plant	Genus Species	NOEL (kg/ha)	EC50 (kg/ha)	Endpoint
Monocotyledone
Corn	Zea mays	16	60	Shoot dry weight
Onion	Allium cepa	16	158	Shoot dry weight
Dicotyledone
Cabbage	Brassica oleracea	32	59.00	Shoot dry weight
Cucumber	Cucumis sativus	4.00	22.0	Shoot dry weight
Lettuce	Lactuca sativa	8.0	30.00	Shoot dry weight
Soy bean	Glycine max	16.00	35.00	Shoot dry weight
Tomato	Lycopersicon esculentum	< 2.0	7.00	Shoot dry weight

Effects of Cyanamid L500 on vegetative vigour (foliar application): Shoot height

Plant	Genus Species	NOEL (kg/ha)	EC50 (kg/ha)	Endpoint
Monocotyledone
Corn	Zea mays	32.00	> 64^a	Shoot height
Onion	Allium cepa	16	3423.47	Shoot height
Dicotyledone
Cabbage	Brassica oleracea	> 64	> 64^a	Shoot height
Cucumber	Cucumis sativus	8.0	31.3	Shoot height
Lettuce	Lactuca sativa	> 32	> 32^a	Shoot height
Soy bean	Glycine max	32	> 64^a	Shoot height
Tomato	Lycopersicon esculentum	8	33.2	Shoot height

Validity criteria fulfilled:

not specified

Conclusions:

The most sensitive endpoint in this study was shoot dry weight for all species. The most sensitive species tested was tomato (Lycopersicon esculentum). The EC50-value for tomato is about 33.2 kg Cyanamid L500/ha which is far above the maximum recommended application rate of 20 kg Cyanamid L500/ha.

Justification for read-across for ecotoxicological endpoints:
Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved, calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar both in chemical structure and regarding fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.
For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Executive summary:

The study was conducted following the accepted test guideline OPPTS 850.4250 (1996): Vegetative vigour dose response test according to GLP.

Non-target terrestrial plant response to formulated cyanamide product, a 50.6 % (w/w) aqueous solution of cyanamide, was evaluated on 7 common plant species at the following dose levels: 2.0, 4.0, 8.0, 16.0, 32.0 and 64.0 kg Cyanamid L500/ha, corresponding to 1.012, 2.02, 4.05, 8.1, 16.19 and 32.38 kg ai/ha. Effects on vegetative vigour and growth following foliar application were assessed.

The most sensitive endpoint in this study was shoot dry weight for all species. The most sensitive species tested was tomato (Lycopersicon esculentum). The EC₅₀-value for tomato is about 33.2 kg Cyanamid L500/ha which is far above the maximum recommended application rate of 20 kg Cyanamid L500/ha.

This information is used in a read-across approach in the assessment of the target substance.

For detailled description where read across is used/recommended and where it is preferrable to refain from read across, please see section 13.2 "read across justification for environmental endpoints" and "Scientific rationale for not using cyanamide as read-across substance for calcium cyanamide on toxicological endpoints"

Description of key information

In the absence of data for calcium cyanamide information on the read-across substance cyanamide is considered in the hazard assessment. (For justification of read-across for environmental endpoints please refer to the document in IUCLID section 13).

Two studies examined the effects of cyanamide on non-target plants, a seedling emergence Tier 2 (LR50) test (Meister, 2001a) and vegetative vigour Tier 2 (LR50) test (Meister, 2001b). In both studies the most sensitive endpoint was shoot dry weight. The most sensitive species in the seedling emergence test was Allium cepa with a EC50 value of 1.722 kg Cyanamid L500/ha (corresponds to 0.87 kg ai/ha). In the vegetative vigour test the most sensitive species was tomato (Lycopersicon esculentum) with a EC50 of 33.2 kg cyanamide L 500/ha (corresponds to 16.8 kg a.i./ha).  

In a long-term toxicity test according to ISO 22030 (2005) the no observed adverse effect concentration (NOAEC) in Avena sativa and Brassica rapa for the endpoints biomass and number of inflorescences per seed pod is ≥ 100 mg a.s./kg soil dry mass (Förster, 2009).

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for terrestrial plants:

100 mg/kg soil dw

Additional information

Environmental fate and exposure are critical factors when assessing environmental risk. Calcium cyanamide is formulated in a slowly dissolving granule (PERLKA) that is applied to agricultural fields as a fertiliser. When dissolved calcium cyanamide is rapidly converted to (hydrogen) cyanamide. These two substances are similar in both chemical structure and fate in the environment. Cyanamide is the environmentally relevant transformation product upon application of calcium cyanamide (PERLKA) to soil as a fertiliser. Therefore, terrestrial data on cyanamide are considered in the hazard assessment of calcium cyanamide.

However, the slow dissolution kinetics of commercially formulated granules (PERLKA) will have a significant effect on cyanamide exposure in the terrestrial environmental compartment, in addition to application frequency and loading.