Cyanamide

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991-05-25 until 1991-07-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: BBA guideline VI, 23-1 (1991)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Application method:

other: oral, inhalation, contact

Analytical monitoring:

no

Details on sampling:

No sampling

Vehicle:

no

Details on preparation and application of test substrate:

The tests were conducted with 51.6 % (w/w) aqueous solution of cyanamide (Alzodef) and applied in a concentration of 20 % (v/v) aqueous solution of the test substance (equivalent to a concentration of 10.32 % (w/w) pure cyanamide or 80 L/ha Alzodef in 400 L water, which is the double of the highest concentration for practical use. ).

Test organisms (species):

Apis mellifera

Animal group:

Hymenoptera (honeybees)

Details on test organisms:

Not indicated

Study type:

laboratory study

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

No post exposure observation

Test temperature:

Not indicated

pH (if soil or dung study):

Not indicated

Humidity:

Not indicated

Photoperiod and lighting:

Not indicated

Details on test conditions:

Test procedures for each treatment plus a control and a toxic reference were performed in 3 cages with 10 honeybees in two replicates. Wotafox-Konzentrat 50 was the toxic standard used in these tests. Bees were observed 24 and 72 hours after treatment for mortality and sub lethal effects.

Nominal and measured concentrations:

The test substance (a 51.6 % (w/w) aqueous solution of cyanamide) was applied at a concentration of 20 %, corresponding to 80 L/ha Alzodef in 400 L water, equivalent to a concentration of 10.32 % (w/w) pure cyanamide.
The test designed to observe the feeding effects of a 51.6 % (w/w) aqueous solution of cyanamide was conducted with a 1 % (v/v) aqueous solution of the test substance (equivalent to a concentration of 0.516 % (w/w) pure cyanamide). Due to high mortality (100%) after 24 hours, additional testing was carried out with concentrations of 0.0516 % and 0.258 % in a 50% sucrose solution according to BBA Guideline VI, 23-1.

Reference substance (positive control):

yes

Remarks:

, Wotafox-Konzentrat 50

Key result

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

< 51.6 µg per animal

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Key result

Duration:

72 h

Dose descriptor:

LC100

Effect conc.:

258 µg per animal

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

Effects as inhalation poison: In the test procedure for the effect as inhalation poison a 10.32 % (w/w) aqueous solution of cyanamide caused 3.3% mortality after 24 hours. All treated bees died after 72 hours. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food.

Effects as indirect contact poison: In the test procedure for the effect as indirect contact poison a 10.32 % (w/w) aqueous solution of cyanamide caused 100% mortality after 24 hours and 72 hours. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food.

Effects as direct contact poison: In the test procedure for the effect as direct contact poison a 10.32 % (w/w) aqueous solution of cyanamide caused 100% mortality after 24 hours and 72 hours, respectively. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food.

Effects as stomach poison: In the test procedure for the effect as stomach poison the bees were offered the test substance at a concentration of 0.516 % in a 50% sucrose solution. Due to high mortality (100%) after 24 hours, additional testing was carried out with concentrations of 0.0516 % and 0.258 % in a 50% sucrose solution according to BBA Guideline VI, 23-1.

After 24 hours, bee mortality in the 0.0516 %, 0.258 % and 0.516 % treatment groups accounted for 41.7 %, 96.7 % and 100 %, respectively. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food. According to the additional testing, the LD50 was less than 100 µg of a 51.6% (w/w) aqueous solution of cyanamide/bee, corresponding to less than 51.6 µg of the pure active ingredient cyanamide.

Results with reference substance (positive control):

Not indicated

Reported statistics and error estimates:

Not indicated

Effects of a 10.32 % (w/w) aqueous solution of cyanamide as inhalation poison to honeybees (% mortality):

	Aqueous solution of cyanamide (10.32 %)		Control		Toxic reference
	24 hours	72 hours	24 hours	72 hours	24 hours	72 hours
Replicate I	3.3	100	0	0	100	100
Replicate II	3.3	100	0	6.7	100	100
Mean	3.3	100	0	3.3	100	100

 

 

Effects of a 10.32 % (w/w) aqueous solution of cyanamide as indirect contact poison to honeybees (% mortality):

	Aqueous solution of Cyanamide (10.32 %)		Control		Toxic reference
	24 hours	72 hours	24 hours	72 hours	24 hours	72 hours
Replicate I	100	100	0	3.3	100	100
Replicate II	100	100	3.3	3.3	100	100
Mean	100	100	1.7	3.3	100	100

 

 

Effects of a 10.32 % (w/w) aqueous solution of Cyanamide as direct contact poison to honeybees (% mortality):

 

	Aqueous solution of Cyanamide (10.32 %)		Control		Toxic reference
	24 hours	72 hours	24 hours	72 hours	24 hours	72 hours
Replicate I	100	100	0	0	100	100
Replicate II	100	100	0	3.3	100	100
Mean	100	100	0	1.7	100	100

 

 

Effects of an aqueous solution of Cyanamide as stomach poison to honeybees
(% mortality):

 

	Aqueous solution of cyanamide (0.0516 %)	Aqueous solution of cyanamide (0.258 %)	Aqueous solution of cyanamide (0.516 %)	Control	Toxic reference
	24 h	24 h	24 h	24 h	24 h
Replicate I	53.3	100.0	100	0	100
Replicate II	30.0	93.3	100	0	100
Mean	41.7	96.7	100	0	100

 

 

Summary of the toxicity data of ALZODEF to bees (given as µg ai/bee):

Acute Endpoint	µg pure cyanamide/bee
Oral LD50	<51.6
Contact LD50	abnormal behaviour and mortality (overspray with 0.2 L product/L spray concentration)

 

Validity criteria fulfilled:

yes

Conclusions:

An LD50 (oral) <51.6 µg ai/bee was determined. Although no LD50 (contact) was determined, abnormal behaviour and mortality following an overspray with 0.2 L Alzodef (cyanamide)/L spray concentration. Therefore cyanamide can be classified as harmful to bees.

Executive summary:

Acute toxicity of ALZODEF® (a 51.6 % (w/w) aqueous solution of cyanamide) to honeybees (Apis mellifera L.) was tested in a laboratory study conducted under BBA Guideline VI 23-1 (1991). These tests were performed to observe respiratory effects, contact effects and residual effects on honeybees of a 51.6 % (w/w) aqueous solution of cyanamide conducted with 20 % (v/v) aqueous solution of the test substance (equivalent to a concentration of 10.32 % (w/w) pure cyanamide). The test designed to observe the feeding effects of a 51.6 % (w/w) aqueous solution of cyanamide was conducted with a 1 % (v/v) aqueous solution of the test substance (equivalent to a concentration of 0.516 % (w/w) pure cyanamide). Test procedures for each treatment plus a control and a toxic reference were performed in 3 cages with 10 honeybees in two replicates. Wotafox-Konzentrat 50 was the toxic standard used in these tests. Bees were observed 24 and 72 hours after treatment for mortality and sub lethal effects.

 

Effects as inhalation poison: In the test procedure for the effect as inhalation poison a 10.32 % (w/w) aqueous solution of cyanamide caused 3.3% mortality after 24 hours. All treated bees died after 72 hours. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food.

 

Effects as indirect contact poison: In the test procedure for the effect as indirect contact poison a 10.32 % (w/w) aqueous solution of cyanamide caused 100% mortality after 24 hours and 72 hours. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food.

 

Effects as direct contact poison: In the test procedure for the effect as direct contact poison a 10.32 % (w/w) aqueous solution of cyanamide caused 100% mortality after 24 hours and 72 hours, respectively. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food.

 

Effects as stomach poison: In the test procedure for the effect as stomach poison the bees were offered the test substance at a concentration of 0.516 % in a 50% sucrose solution. Due to high mortality (100%) after 24 hours, additional testing was carried out with concentrations of 0.0516 % and 0.258 % in a 50% sucrose solution according to BBA Guideline VI, 23-1. After 24 hours, bee mortality in the 0.0516 %, 0.258 % and 0.516 % treatment groups accounted for 41.7 %, 96.7 % and 100 %, respectively. Sublethal effects included irritations, trouble, paralysation, dorsal position and refusal of food. According to the additional testing, the LD50 was less than 100 µg of a 51.6% (w/w) aqueous solution of cyanamide/bee, corresponding to less than 51.6 µg of the pure active ingredient cyanamide. Although no LD50 (contact) was determined, abnormal behaviour and mortality following an overspray with 0.2 L Alzodef (cyanamide)/L spray concentration were observed.

Reference 2

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000-05-23 until 2000-05-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Methodical improvements of standard laboratory tests for determining the side effects of agrochemicals on predatory mites (Louis & Ufer, 1995). Current improvements of the ring-test group (Blümel et al., 1999).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Application method:

other: Exposure of Typhlodromus pyri to dried residues of SKW Cyanamid L500 (a 51.1 % (w/w) aqueous solution of cyanamide) on treated glass plates.

Analytical monitoring:

no

Details on sampling:

No sampling

Vehicle:

no

Details on preparation and application of test substrate:

Not indicated

Test organisms (species):

Typhlodromus pyri

Animal group:

Acari (leaf-dwelling predatory mite)

Details on test organisms:

Not indicated

Study type:

laboratory study

Limit test:

no

Total exposure duration:

7 d

Post exposure observation period:

No post exposure observation period

Test temperature:

Not indicated

Humidity:

Not indicated

Photoperiod and lighting:

Not indicated

Details on test conditions:

Adult mortality and reproductive effects (expressed as fertile egg production/female) were evaluated following a 1-week exposure of Typhlodromus pyri to dried residues of SKW Cyanamid L500 on treated glass plates.
An untreated control and toxic standard (3.6 g Dimethoate/ha) were also tested.

Nominal and measured concentrations:

The application rates were equivalent to 196 g, 339 g, 587 g, 1018 g and 1761 g of a 51.1 % (w/w) aqueous solution of cyanamide per ha and a spray volume of 200 L water/ha. These rates equate to 100 g, 173 g, 300 g, 520 g and 900 g pure active substance cyanamide.

Reference substance (positive control):

yes

Remarks:

Dimethoate (395.7 g/L)

Key result

Duration:

7 d

Dose descriptor:

LR50

Effect conc.:

445.6 g/ha

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

Mortality in the control and toxic standard groups was 5 % and 89.5 %, respectively. The reproduction of surviving mites was not affected at rates up to 173 g pure cyanamide/ha. At 300 g cyanamide/ha the reproduction rate was significantly reduced. At a rate 520 g pure cyanamide/ha, reproductive performance was not significantly different from the control.

Results with reference substance (positive control):

Mortality in the toxic standard group was 89.5% (in the control group, 5%)

Reported statistics and error estimates:

The test groups were significantly different from the control, examined by Dunnet-test, α=0.05

Effects on the predatory mite, Typhlodromus pyri, exposed 7 days to a 51.1 % (w/w) aqueous solution of cyanamide:

Nominal concentrations of cyanamide (g as/ha)	% Mortality (Abbott's correction)	% Reduction in reproduction
100	8.8 %	10.0 %
173	10.5 %	28.0 %
300	36.8 %	36.0 %*
520	38.6 %	16.0 %
900	91.2 %	Not determined
Endpoints
LR50	445.6

 

Validity criteria fulfilled:

yes

Conclusions:

The LR50 value was determined to be 445.6 g pure cyanamide/ha with 95 % confidence limits of 382.6 g cyanamide/ha and 518.9 g cyanamide/ha. The reproduction of surviving mites was not affected at rates up to 173 g pure cyanamide/ha. At a rate of 520 g pure cyanamide/ha reproductive performance was not significantly different from the control.

Executive summary:

Adult mortality and reproductive effects (expressed as fertile egg production/female) were evaluated following a 1-week exposure of Typhlodromus pyri to dried residues of SKW Cyanamid L500 on treated glass plates. The application rates were equivalent to 196 g, 339 g, 587 g, 1018 g and 1761 g of a 51.1 % (w/w) aqueous solution of cyanamide per ha and a spray volume of 200 L water/ha. These rates equate to 100 g, 173 g, 300 g, 520 g and 900 g pure active substance cyanamide. An untreated control and toxic standard (3.6 g Dimethoate/ha) were also tested.

 

Mortality in the control and toxic standard groups was 5 % and 89.5 %, respectively.

 

The LR50 value was determined to be 445.6 g pure cyanamide/ha with 95 % confidence limits of 382.6 g cyanamide/ha and 518.9 g cyanamide/ha. The reproduction of surviving mites was not affected at rates up to 173 g pure cyanamide/ha. At a rate 520 g pure cyanamide/ha, reproductive performance was not significantly different from the control.

Description of key information

The effect of the test substance cyanamide was examied on a variety of terrestrial beneficial arthropods. To most of the examined species (but not to all) in most of the studies the test substance was found to be harmful.

The lowest LR50 values obtained from the dose-response tests with Typhlodromus pyri and Aphidius rhopalosiphi were 445.6 g pure cyanamide/ha and 432.1 g pure cyanamide/ha respectively.
In a dose-response test with the collembolan species Folsomia candida, the EC10 for reproduction was determined to be 1.515 mg pure cyanamide/kg soil dw. This value represents the chronic worst case value for terrestial organisms and is used for risk assessment.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil dwelling arthropods:

1.515 mg/kg soil dw

Additional information

Cyanamide tested under worst-case laboratory conditions as an aqueous solution of cyanamide on honey bees and other beneficial arthropods proved to be harmful to bees, Aphidius rhopalosiphi, Pardosa spec., Chrysoperla carnea, Aleochara bilineata and harmless to Poecilus cupreus. In dose-response tests with Typhlodromus pyri and Aphidius rhopalosiphi, the LR50 was determined to be 445.6 g pure cyanamide/ha and 432.1 g pure cyanamide/ha, respectively. In an extended laboratory test (aged residues) with Aleochara bilineata it was classified as harmless according to the IOBC hazard rating scheme. In a dose-response test with the collembolan species Folsomia candida, the EC10 for reproduction was determined to be 1.515 mg pure cyanamide/kg soil dw. The corresponding toxicity endpoint values are summarised in the following table:

Species	Test	Measurement endpoint	Endpoint value
Apis mellifera	Oral contact (overspray with 0.2 L product/L)	LD50	<51.6 µg pure cyanamide/bee Abnormal behaviour and mortality
Aphidius rhopalosiphi	acute laboratory test	mortality	100 %
Aphidius rhopalosiphi	dose-response test	mortality	LR50= 0.432 kg pure cyanamide/ha
Aphidius rhopalosiphi	dose-response test	mortality	LR50= 0.620 kg pure cyanamide/ha
Chrysoperla carnea	acute laboratory test	mortality	92 %
Chrysoperla carnea	dose-response test	mortality	LR50= 3.4 kg pure cyanamide/ha
Aleochara bilineata	dose-response test	reproduction	ER50= 0.93 kg pure cyanamide/ha
Aleochara bilineata	acute laboratory test	reproduction	99.7 %
Aleochara bilineata	extended laboratory test	reduction of reproduction	15.6 %
Poecilus cupreus	acute laboratory test	mortality/reduction of feeding rate	1.4 %
Pardosa spec.	acute laboratory test	mortality/reduction of feeding rate	100 %
Pardosa spec.	dose-response test	mortality	LR50= 2.1 kg pure cyanamide/ha
Typholodromus pyri	dose-response test	mortality	LR50= 0.446 kg pure cyanamide/ha
Typholodromus pyri	dose-response test	mortality	LR50= 2.07 kg pure cyanamide/ha
Folsomia candida	dose-response test	reproduction	EC10=1.515 mg pure cyanamide/kg soil dw