OSHA Inspection: FAMILY DENTAL GROUP

Issued

Jun 11, 1987

Abate by

Nov 30, 1987

Penalty

Initial $480 · Current $280 Reduced

Hazardous substances 1953

General-duty citation text

Section 5(a)(1) of the Occupational Safety and Health Act of 1970: The
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employer did not furnish employment and a place of employment which were
free from recognized hazards that were causing or likely to cause death
or serious physical harm to employees in that employees were exposed to
the hazards of nitrous oxide present as a waste anesthetic gas while
performing and assisting with dental operatory procedures. The employer
did not provide controls during the period of administration of nitrous
oxide in order to control occupational exposure to waste nitrous oxide
gas. The employees were exposed to high levels of nitrous oxide thereby
subjecting them to serious health hazards of:
1) an increased incidence of liver and kidney diseases;
2) an increased rate of spontaneous abortions to female exposed to the
nitrous oxide gas;
3) an increased rate of congenital abnormalities to children born to
parents either or both of whom were exposed to nitrous oxide; and,
4) increased rate of development of neurological diseases.
a) A dental surgeon, while performing dental surgeries, was exposed to a
concentration of 1110 ppm of nitrous oxide for 143 minutes on April
23, 1987, The 8-hour time-weighted average (TWA) for this exposure is
331 ppm which is 13.3 times the acceptable limit.
b) An office manager/dental assistant, while assisting during dental
surgery, was exposed to a concentration of 416 ppm of nitrous oxide
for 150 minutes on April 23, 1987. The 8-hour TWA for this exposure
is 130 ppm which is 5.2 times the acceptable limit.
c) A patient coordinator, while working at the reception desk, was
exposed to a concentration of 369 ppm of nitrous oxide for 145
minutes on April 23, 1987. The 8-hour TWA for this exposure is 112
ppm which is 4.5 times the acceptable limit.
NIOSH's occupational exposure to nitrous oxide, when used as the sole
anaesthetic agent, shall be controlled so that no worker is exposed
to TWA concentrations greater than 25 ppm during anaesthetic
administration.
Some feasible and acceptable abatement methods, among others to correct
this hazard are;
1) Installation of a scavenging exhaust systems;
2) Leak testing both the high and low pressure nitrous oxide delivery
systems to assure tight fit of all parts and a minimum of leakage;
3) Minimizing conversation with the patient during nitrous oxide dental
operations;
4) Performing preventive maintenance of anaethesis equipment at least
semi-annually;
5) Employing the air sweep when acceptable concentrations of nitrous
oxide are not achieved by other methods;
6) Assuring that the exhaust vacuum flow rate should be kept at 45 LPM;
7) Assuring that the scavenging exhaust system is vented to prevent any
recontamination of the room;
8) Increasing general room dilution ventilation rates;
9) Employ ongoing air monitoring program to verify the effectiveness of
the control measures; and,
10) Administratively control the nitrous oxide, such as but not limited
to:
a) limiting the number of nitrous oxide surgeries per day;
b) rotation of personnel who utilize nitrous oxide during their workday.
ABATEMENT SCHEDULE
STEP 1: Submit to the Area Director a written, detailed plan of
abatement outlining a schedule for the implementation of engineering
or administrative measures to control employees exposure to hazardous
substances as referenced in this citation. This plan shall include at
a minimum, target dates for the following actions which must be
consistent with abatement dates required by this citation:
1) Evaluation of engineering/administrative control options;
2) Selection of optimum control methods and completion of design;
3) Procurement, installation and operation of selected control measures;
4) Testing and acceptance of modification/redesign of controls.
All proposed control measures shall be evaluated for each particular
use by a competent industrial hygienist or other technically
qualified person. Thirty (30) day progress reports are required
during the abatement period.
STEP 2: Abatement shall have been completed by the implementation of
feasible engineering and/or administrative controls upon verification
of their effectiveness in achieving compliance.

Issued

Jun 11, 1987

Abate by

Jun 22, 1987

Hazardous substances 82101953

Issued

Jun 11, 1987

Abate by

Jun 22, 1987

Hazardous substances 19538210

Issued

Jun 11, 1987

Abate by

Jul 31, 1987

Hazardous substances 8210