T

H

E

E

N

V

IR

O

N

M

E

N

T

I

NFECTION

C

ONTROL IN THE

P

HYSICIAN

’

S

O

FFICE

43

Table 3 - High-Level Disinfectants (HLD)

Chemical

Action

Application

Exposure Time

Comments

Glutaraldehyde

Sterilant
HLD

Semi-critical
devices

>20 minutes for
HLD

>10 hours for
sterilization (or
according to
manufacturer’s
recommenda-
tions)

• Toxic. Rinse well.

• Shelf life limited.

• Requires well-ventilated room and safe work practices. Health care

workers may be exposed to elevated vapour if equipment is
processed in rooms with inadequate ventilation, when spills occur, or
when there is an open immersion bath. The ceiling exposure value
(CEV) is the maximum airborne concentration of a biological or
chemical agent to which a worker is exposed at any time. The current
occupational exposure limit that the Ontario Ministry of Labour has
set for glutaraldehyde is a ceiling exposure value of 0.05 ppm.

• The recommended in-use concentration of each preparation should

be maintained for the product to maintain its effectiveness, therefore
monitoring the concentration of glutaraldehyde is required. Follow
manufacturers’ recommendations.

Ortho-phtha-
laldehyde
0.55%

HLD

Semi-critical
devices

12 minutes

• Shelf life limited.

• Less occupational risks.

• Rinse well.

Sodium
hypochlorite
1,000 parts per
million (ppm)
(1:50 dilution of
household
bleach)

HLD

Limited
application
on semi-criti-
cal devices

>20 minutes

• Corrosive to metals.

• Rinse well.

• Does not clean.

• If stored in opaque container can be prepared weekly. Otherwise,

prepare daily.

Boiling

HLD

Semi-critical
items that
can be sub-
jected to
moisture and
heat

>20 minutes

• Change water daily.

• Clean vessel daily.

• Keep water level full.

Table 4 - Intermediate/Low-Level Disinfectants (I/LLD)

Chemical

Action

Application

Exposure Time

Comments

Sodium
hypochlorite,
500 ppm (1:100
dilution of
household
bleach)

I/LLD

Environmental
surfaces

10 minutes

• Clean surface first, then disinfect.

• Store in opaque container away from light – can be prepared

weekly.

Alcohol, iso-
propyl 60-90%

ILD

Environmental
surfaces

Allow to dry

• Clean surface first, then disinfect.

Table 5 - Low-Level Disinfectants (LLD)

Chemical

Action

Application

Exposure Time

Comments

• Quaternary ammonium

compounds

• Accelerated hydrogen

peroxide products

• Sodium hypochlorite

(1:100 dilution of house-
hold bleach)

• Phenolics

LLD

Daily cleaning
and disinfection
of all surfaces in
the office

• Sodium hydrochlorite is a disinfectant

agent and has no cleaning properties.

• Phenols may leave a film; may depigment

skin; do not use on items that will be used
with infants.