Genetic Toxicology - Mammalian Cell Mutagenicity

Study Information
Study Attribute	Value
CEBS Accession Number:	002-01820-0014-0000-8
Chemical Name:	Calcium chromate
CASRN:	13765-19-0
NTP Study Type:	Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID:	G00668
Study Result:	Positive

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Table Instructions and Notes:
Studies are indicated to be "Nontoxic" when the observed reductions in relative total growth did not indicate that the maximum tolerated dose was achieved.

Nonactivation Trial: 1 Experiment Call: No Call
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Dimethyl Sulfoxide	0	86	91	48	19	17
Vehicle Control			74	102	34	15	17
Test Chemical	Calcium chromate	0.625	93#	116	79.5	29	27
			84	93	64	25	27
		1.25	77	74	180	78	67*
			73#	70	121.5	56	67*
		2.5	83#	40	346	139	121*
			87	47	269	103	121*
		5	42#	17	306	244	254*
			54	24	426	263	254*
		10	20	3	260	444	430*
			18	2	222	415	430*
		20

Positive Control	Ethyl Methane Sulfonate	500	61	38	923	504	516*
Positive Control			52#	39	831	528	516*
Negative Control	Negative (Not Specified)	0	84	122	33	13	11*
Negative Control			80#	85	23	10	11*

Nonactivation Trial: 2 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	50	103	8	5	13
Vehicle Control			50	89	31	21	13
Test Chemical	Calcium chromate	0.625	42	104	21	17	16
			30	70	14	16	16
		1.25	51	104	65	42	46*
			37	68	56	50	46*
		2.5	42#	61	93	75	75*
			46	64	104	75	75*
		5	28#	27	126	150	146*
			34	34	147	143	146*
		10	12	3	93	270	279*
			16	4	141	288	279*
		20

Positive Control	Ethyl Methane Sulfonate	500	37#	41	463	417	407*
Positive Control			26	39	310	397	407*
Negative Control	Negative (Not Specified)	0	42r	112	12	10
Negative Control			55	107	19	11

Nonactivation Trial: 3 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	98	135	83	28	32
			99	71	104	35
			97	88	102	35
			101	106	85	28
Test Chemical	Calcium chromate	0.625	108	106	101	31	30
			97	93	86	29	30
		1.25	97	72	150	51	50*
			91	71	134	49	50*
		2.5	83	73	156	63	64*
			89	66	172	65	64*
		5	79	41	309	131	143*
			87	44	400	154	143*
		10	68	26	515	254	270*
			62	26	533	286	270*
		15	27	3	630	783
Positive Control	Ethyl Methane Sulfonate	500	64	30	1180	613	546*
Positive Control			69	35	985	478	546*

Nonactivation Trial: 4 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	64	107	37	19	20
			82	84	60	24
			74	105	39	18
			82	104	49	20
Test Chemical	Calcium chromate	0.625	71	82	11	5	8
			91	116	27	10	8
		1.25	56	104	35	21	18
			99	128	46	16	18
		2.5	81	81	81	33	31
			60	64	53	29	31
		5	83	69	162	65	68*
			64	65	136	71	68*
		10	54	34	155	95	100*
			78	47	246	106	100*
		15	44	20	183	138	145*
			43	21	197	153	145*
Positive Control	Ethyl Methane Sulfonate	500	32	23	530	552	796*
			14	9	458	1131
			21	16	447	704

Non-Induced S9 Trial: 1 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	91	112	57	21	25
Vehicle Control			68	80	61	30	25
Test Chemical	Calcium chromate	3.75	52	46	45	29	32
			60	50	62	34	32
		7.5	51	40	138	90	92*
			42	31	118	93	92*
		15	45	16	452	337	271*
			58	28	356	205	271*
		30

Positive Control	3-Methylcholanthrene	7	126r	46	402	107	171*
Positive Control			96	25	492	171	171*
Negative Control	Negative (Not Specified)	0	105	119	70	22	27*
Negative Control			75#	89	70	31	27*

Non-Induced S9 Trial: 2 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	97	117	45	15	18
Vehicle Control			82	91	51	21	18
Test Chemical	Calcium chromate	3.75	83	87	121	49	63*
			75	90	174	78	63*
		7.5	71	52	336	157	157*
			52	41	243	157	157*
		10	60#	22	304.5	170	158*
			67	24	295	146	158*
		15	35	8	277	264	342*
			16	2	202	421	342*
		20

Positive Control	3-Methylcholanthrene	7	84	32	454	181	162*
Positive Control			93#	36	397	143	162*
Negative Control	Negative (Not Specified)	0	68	101	27	13	17*
Negative Control			74	90	44	20	17*

Induced S9 Trial: 1 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	80#	101	76.5	32	33
Vehicle Control			79	90	79	33	33
Test Chemical	Calcium chromate	3.75	49	56	59	40	36
			63	94	58	31	36
		7.5	54	45	160	100	100*
			74	76	221	99	100*
		15	55	36	384	233	260*
			45	24	384	287	260*
		30

Positive Control	3-Methylcholanthrene	5	29	6	335	385	419*
Positive Control			39#	6	522	452	419*
Negative Control	Negative (Not Specified)	0	85	104	95	37	38*
Negative Control			96	106	110	38	38*

Induced S9 Trial: 2 Experiment Call: No Call
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	60	98	54	30	38
Vehicle Control			52#	121	70.5	45	38
Test Chemical	Calcium chromate	0.94	70#	107	82	39	43
			67	84	95	47	43
		1.88	73#	117	121	55	54
			66#	93	106	53	54
		3.75	65	84	161	83	83*
			62	73	153	82	83*
		7.5	51	53	217	141	139*
			75	67	306	137	139*
		15	25	10	273	359
		20

Positive Control	3-Methylcholanthrene	5	22#	7	132	205	248*
Positive Control			17	5	146	292	248*
Negative Control	Negative (Not Specified)	0	75	81	115	51
Negative Control			50r	79	100	67

Induced S9 Trial: 3 Experiment Call: Positive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Water	0	71	115	50	23	23
			60	83	41	23
			84	109	53	21
			66	93	47	24
Test Chemical	Calcium chromate	2.5	41	45	74	60	55*
			36	43	54	50	55*
		5	35	36	112	108	87*
			48	42	94	66	87*
		10	40	28	153	127	137*
			43	32	162	125
			33	28	160	161
		15	42	21	191	153	154*
			31	17	166	178
			43	18	165	129
		20	19	8	111	198	264*
			12	7	139	376
			25	9	164	217
		30


Positive Control	3-Methylcholanthrene	5	36	16	254	233	231*
			33	16	232	233
			29	17	195	227

Footnotes:
Asterisks(*) indicate significant responses.
r = rejected value due to quality control criteria
# = reduced sample size because of the loss of one culture dish due to contamination