Regulation and Risk Assessment of 1,4-Dioxane - Environmental Investigation and Remediation - page 310

TABLE 6.24 (continued)
Relative Risk Thresholds of Solvent Stabilizers Compounds

Carcinogenicity,
Mutagenicity, and
Genotoxicity

Stabilizer Oral Rat LD 50 Inhalation LC 50 NOAEL

Phenol 317 mg/kg [2]

530 mg/kg [10]

LC 50 rat inhalation
316 mg/m 3 [11]

1000 ppm = NOAEL
for reproductive
toxicity, in drinking
water supplied to
rats [12]

IRIS D: Not classii able as to
human carcinogenicity [10];
IARC group 3: Not
classii able as to its
carcinogenicity to
humans [6]

Triethylamine 460 mg/kg [13] 1000 ppm for 4 h [14] 247 ppm = NOAEL

for rat inhalation
[15]

A4: Not classii able as a
human carcinogen [5]

1,2-Butylene oxide 500 mg/kg [16]

1170 mg/kg [17]

398-6550 ppm for
4 h [18] 200 ppm:
Rat inhalation for
6 h/day, 5 day/
week, 65 exposures
in total [18]

None observed [19]
<50 ppm [17]

Male rats = clear evidence;
female rats = equivocal
evidence; male and female
mice = no evidence [17];
nasal carcinogen in male
rats [20]

Diisopropylamine 770 mg/kg [2] 4800 mg/m 3 for

2 h [2]

41 ppm = rat
inhalation, 6 h/day, 5
day/week, 4 weeks
[21]

Not carcinogenic; negative
mutagenicity and
genotoxicity [22]

Nitromethane 940 mg/kg [14] Central nervous

system symptoms
with exposures at
3% or 5% vapors for
>1 h or 1%
nitromethane for 5 h
in rabbits and guinea
pigs [23]

200 ppm = rat
inhalation, 6 h/day, 5
day/week, 4 weeks
[24]

A3: Coni rmed animal
carcinogen with unknown
relevance to humans [5];
clear evidence of
carcinogenic activity of
nitromethane in rats and
mice [25]; cancer potency
0.18 (mg/(kg d)) -1 ; No
Signii cant risk level = 39
μg/d [26]

tert -Amyl alcohol 1000—2000 mg/

kg [27]

14,000 mg/m 3 for 6 h
in rat [28]

225 ppm in rats [29] —

Nitroethane 1100 mg/kg [2] — — Not carcinogenic [20]

2-Methyl-3-butyn-
2-ol

1420 mg/kg [30] 50 mg/kg of body

weight [30]

No animal data or information
on potential human
carcinogenicity [30]

>21,300 mg/m 3 [30]

1,3-Dioxolane 2000 mg/kg [31]

3000 mg/kg [32]
5200 mg/kg [33]

4-h acute LC 50 is
68.4 mg/L [34]

500 ppm rat
inhalation [33]

Not likely to be carcinogenic
[33]; dioxolane did not
induce chromosomal
aberrations;
not mutagenic [35]

Butoxymethyl
oxirane ( n -butyl
glycidyl ether)

“2000 mg/kg” [36]
2050 mg/kg [37]

670 ppm [38] 25 ppm rat inhalation;

6 h/day, 5 day/week;
13 weeks [39]

n -Butyl glycidyl ether was
mutagenic in vitro in various
bacterial and mammalian
cells and produced
chromosomal aberrations in
an in vitro assay [40]

continued